Form 485BPOS ARIEL INVESTMENT TRUST

3.   Board Reporting. The Chief Compliance Officer will provide the following quarterly reporting to the following Boards:

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I.   Enforcement and Sanctions

1.   Penalties for Violations of this Code. The Chief Compliance Officer will take any action he/she deems appropriate against any
Advisory Person who violates any provision of this Code. Such action may include:

2.   Reporting Code Violations to the Trust’s Board of Trustee’s, Ariel Investments’ Board of Directors and/or Ariel
Alternatives Board of Managers. Each violation of this Code by Advisory Persons associated with the Trust and Ariel Investments will be reported to the Trust’s Board of Trustees and Ariel Investments’ Board of Directors at or before
the respective Board’s next regular meeting. Violations of this Code by Advisory Persons associated with Ariel Alternatives will be reported to Ariel Alternatives Board of Managers. The Trust’s Board of Trustees, Ariel Investments Board of
Directors and Ariel Alternatives Board of Managers may impose sanctions in addition to those imposed by the Chief Compliance Officer.

3.   Safe Harbor from Sections E.5 and D.2 Violations. The Chief Compliance Officer may make a written determination that an Advisory
Person who sold a de minimis position of a Reportable Security without obtaining prior approval did not violate Section E.5 of the Code.

4.   Safe Harbor from Section E.6 Violations. The Chief Compliance Officer may make a written determination that an Advisory Person
who opened a Reportable Account without reporting it on the same day as the account’s inception or obtaining prior approval did not violate Section E.6 of the Code if such person had not yet made any transactions in the applicable Reportable
Account.

J.   Administration of the Code

1.   Administration of the Code. The Chief Compliance Officer will administer the Code, using reasonable diligence and instituting
procedures reasonably necessary to prevent Code violations. Among other things, the Chief Compliance Officer will review reports submitted by Advisory Persons against pre-clearance requests, transaction
confirmations and account statements on a quarterly basis, and look for unusual or very large trades, which may indicate insider trading.

2.   Recordkeeping. The Chief Compliance Officer will maintain a record of all Code violations, and of any action taken as a result
of the violation. The record of violations will be maintained for five years in an easily accessible place.

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3.   List of Advisory Persons. The Chief Compliance Officer will prepare a list of the
Advisory Persons, update the list as necessary, and maintain former lists.

4.   Notice of Amendments to the Code. The Chief
Compliance Officer will provide you with all Code amendments, and you will acknowledge receipt of all amendments.

5.   Exceptions
and Exemptions. The Chief Compliance Officer may grant an exception to or exemption from this Code to any person, transaction or series of transactions, provided that the exception or exemption is not contrary to the mandatory requirements of
the 1940 Act or the Advisers Act. Exceptions or exemptions must be in writing and specify the Code section(s) from which the person, transaction or series of transactions is excepted or exempted, the reasons for the exception or exemption and any
conditions related to the exception or exemption.

6.   Annual Report for the Trust, Ariel Investments, Ariel Alternatives and
Project Black ManCo. At least once a year, the Chief Compliance Officer will furnish to the Trust’s Board of Trustees, Ariel Investments’ Board of Directors, and Ariel Alternatives Board of Managers, and the respective Boards will
consider, a written report that:

7.   Changes to the Code. The Trust’s Board of
Trustees (including a majority of the Disinterested Trustees voting separately) will consider and determine whether to approve any material change to this Code at its next regular Board meeting after such change, and in no event more than six
(6) months thereafter.

8.   Maintaining Copies of Versions of the Code. A copy of each version of the Code will be
maintained for five (5) years in an easily accessible place.

9.   Disclosure. The Code will be described in the applicable
Ariel entity’s Form ADV, Part 2A, and a copy of the Code will be provided to any Client or prospective Client upon request.

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EXHIBIT A

INSIDER TRADING POLICY AND PROCEDURES

1.  
Insider Trading Policy

As set forth in Code Section D.7, all directors, trustees, officers, board of manager members, advisory board members or
employees of the Trust, Ariel Investments, Ariel Alternatives, Project Black ManCo and the Distributor are prohibited from trading in any security, either personally or on behalf of others, including Ariel Investments’ Clients such as the Trust
and Ariel Alternatives’ and Project Black ManCo’s Clients, on the basis of material nonpublic information or communicating material nonpublic information to others in violation of the law. This conduct is frequently referred to as
“insider trading.” Federal securities laws prohibit insider trading and such laws may extend to activities within and outside your duties at the Trust, Ariel Investments, Ariel Alternatives, Project Black ManCo, or the Distributor.

Ariel Investments, Ariel Alternatives, Project Black ManCo, and Distributor employees must notify the Chief Compliance Officer immediately if they have any reason to
believe that a violation of this policy has occurred or is about to occur. Employee questions regarding this policy should be referred to the Chief Compliance Officer.

The term “insider trading” generally is used to refer to the use of material nonpublic information to trade in securities (whether or not one is an
“insider”) or to communication of material nonpublic information to others.

The law concerning insider trading is generally understood to prohibit:

Who is an Insider?

The concept of
“insider” is broad, and includes a company’s officers, directors, trustees, and employees. Each director, trustee, officer, manager, or employee of the Trust, Ariel Investments, Ariel Alternatives, Project Black ManCo and the
Distributor is considered an insider of his or her respective company or companies.

A person can be a “temporary insider” if he enters
into a special confidential relationship in the conduct of a company’s affairs and as a result is given access to information solely for the company’s purposes. A temporary insider can include, among others, a company’s attorneys,
accountants, consultants, bank lending officers, and the employees of such organizations. Additionally, Ariel Investments, Ariel Alternatives, Project Black ManCo or the Distributor may become a temporary insider of a company they advise or for
which they perform other services. To be an insider, the company must expect the outsider to keep the disclosed nonpublic

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information confidential, and the company’s relationship with an insider must at least imply such a duty.

What is Material Information?

Trading
on inside information is not a basis for liability unless the information is material. “Material Information” generally is defined as information for which there is a substantial likelihood that a reasonable investor would consider it
important in making his or her investment decisions, or information that is reasonably certain to have a substantial effect on the price of a company’s securities.

Information that should be considered as material includes, but is not limited to: dividend changes, earnings estimates, changes in previously
released earnings estimates, significant merger or acquisition proposals or agreements, major litigation, liquidation problems, and extraordinary management developments.

Material Information also may relate to the market for a company’s securities. Information about a significant order to purchase or sell
securities may, in some contexts, be deemed material. Similarly, prepublication information regarding reports in the financial press also may be deemed material. Moreover, advance reports of securities to be bought or sold by a large, influential
institutional investor, such as the Trust, may be deemed material to an investment in those portfolio securities.

Advance knowledge of important
proposed government regulation, for example, could also be deemed material information regarding companies in regulated industries.

What is
Nonpublic Information?

Information is nonpublic until it has been broadly distributed to the public marketplace. For example, information is
public after it has become available to the general public through a public filing with the Securities and Exchange Commission or some other governmental agency, the Dow Jones “tape” or The Wall Street Journal or some other
publication of general circulation or the internet, and after sufficient time has passed so that the information has been widely distributed.

Penalties for Insider Trading.

Civil
and criminal penalties for trading on or communicating material nonpublic information are severe, both for individuals involved in such unlawful conduct and their employers. A person can be subject to some or all of the penalties below even if
he or she does not personally benefit from the violation. Penalties include:

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In addition, employee violations of this policy can be expected to result in serious sanctions by Ariel Investments,
Ariel Alternatives, Project Black ManCo and/or the Distributor, including dismissal.

2.   Identifying Inside Information

Before any Ariel entity employee covered by this policy executes any trade for the employee or on the behalf of others, including the Trust, in the securities of a
company about which the employee may have potential inside information, the following questions should be considered:

If, after consideration of the above, it is found that the information is material and nonpublic, or if the person has questions as to whether
the information is material and nonpublic, Ariel entity employees should take the following steps before any trade is executed:

Disinterested Trustees,
Disinterested Directors and Outside Board Members are encouraged to discuss any questions regarding potential inside information relating to Ariel Investments, the Trust, Ariel Alternatives or Project Black ManCo with counsel for Ariel Investments,
Ariel Alternatives, Project Black ManCo, the Trust or Independent Trustees.

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3.   Contacts with Public Companies

Contacts with public companies represent an important part of Ariel Investments’, Ariel Alternatives’, and Project Black ManCo’s research efforts.
Ariel Investments, Ariel Alternatives and Project Black ManCo may make investment decisions on the basis of the firm’s conclusions formed through such contacts and analysis of publicly available information. Difficult legal issues arise,
however, when, in the course of these contacts, an Ariel Investments, Ariel Alternatives or Project Black ManCo employee or other person subject to this policy becomes aware of material, nonpublic information. This could happen, for example, if a
company’s Chief Financial Officer prematurely discloses quarterly results to the analyst or an investor relations representative makes a selective disclosure of adverse news to a handful of investors. In such a situation, Ariel Investments,
Ariel Alternatives and/or Project Black ManCo (as applicable) must make a judgment as to its further conduct. For the protection of the company and its employees, the Chief Compliance Officer should be contacted if an employee believes that Ariel
Investments, Ariel Alternatives, Project Black ManCo or its employees have received material, nonpublic information.

4.   Expert Networks

Ariel Investments’ policy is not to utilize expert network firms in connection with its investment research. This policy is set forth in
Section 8.8 of Ariel Investments’ compliance manual (pertaining to portfolio management). If an Ariel Investments’ research team employee would like to utilize such a firm, the procedures therein require, among other things, prior
written approval by the team’s Director of Research and the Chief Compliance Officer.

Ariel Alternatives’ and Project Black ManCo’s policy
allows for the utilization of expert network firms in connection with its investment research so long as such utilization is approved, in advance, by the Chief Compliance Officer, and controls imposed by the Chief Compliance Officer are followed
by the business.

5.   Tender Offers

Tender offers
represent a particular concern in the law of insider trading for two reasons. First, tender offer activity often produces extraordinary gyrations in the price of the target company’s securities. Trading during this time period is more likely to
attract regulatory attention (and produces a disproportionate percentage of insider trading cases). Second, the Securities and Exchange Commission has adopted a rule which expressly forbids trading and “tipping” while in possession of
material, nonpublic information regarding a tender offer received from the tender offeror, the target company or anyone acting on behalf of either. Persons subject to this policy should exercise particular caution any time they become aware of
nonpublic information relating to a tender offer.

6.   Service on Company and Non-Profit Boards of
Directors

Ariel Investments does not buy for its clients securities of privately held companies or securities issued by a public company for which an
Ariel Investments employee serves as a director. Ariel Alternatives and Project Black ManCo do not buy for its clients securities issued by a public company for which an Ariel Alternatives or Project Black

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ManCo employee serves as a director. That said, employees serving on company or non-profit boards of directors may receive material, nonpublic inside
information about other public companies. These employees should contact the Chief Compliance Officer in accordance with the procedures set forth in Section 2 “Identifying Inside Information” above.

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EXHIBIT B

SUPPLEMENTAL PROCEDURES FOR DISCRETIONARY ACCOUNTS

The
following procedures govern the Code’s requirements for Discretionary Accounts.

1.   Accounts qualifying as Discretionary. To qualify as a
Discretionary Account, you and the trustee, broker or adviser (“third party manager”) for the account will agree that you or your Immediate Family Member or Domestic Partner will not have any direct or indirect influence or control over
the account. You or your Immediate Family Member or Domestic Partner may, however: (a) inform the third party manager of general investment objectives, such as a need for income, the degree of risk tolerance, and general mix and asset
allocation guidelines; and (b) receive confirmation statements or monthly statements in regular course after transactions are effected. You or your Immediate Family Member or Domestic Partner may not either direct or suggest to the third party
manager any purchases or sales of investments, or consult with the third party manager as to the particular allocation of investments to be made in the account.

2.   Prior Approval of these Accounts Required. In order to be exempt from the provisions outlined in paragraph 3 below, you must obtain prior
written approval of the Chief Compliance Officer before opening a Discretionary Account. You should discuss the proposed account with the Chief Compliance Officer, who will review the identity of the account holder; the identity of the trustee,
broker or adviser having investment discretion; and the written terms of the arrangement.

3.   Code Exemptions for Approved Discretionary
Accounts. An approved Discretionary Account relieves you ONLY from the prohibitions of Section D (other than the prohibitions of D.7) and the reporting obligations imposed by Sections E.3, E.4 and E.5, and the reporting obligations imposed by
Section E.2 relating only to Reportable Securities. You are still subject at all times to general insider trading restrictions as well as the high fiduciary standards expected from all Advisory Persons.

4.   Initial and Annual Certifications. You will initially and annually certify, in substantially the following form:

The undersigned certifies that, as of this day and for the period since the last certification or the establishment of the Discretionary Account, you
or your Immediate Family Member or Domestic Partner has had no direct or indirect influence or control over any particular transaction made or to be made in the account and the third party manager has made all investment decisions without informing
you or your Immediate Family Member or Domestic Partner as to the transaction until after the transaction has been effected.

5.   Termination of
Arrangements. If at any time you or your Immediate Family Member or Domestic Partner determines to exercise any influence or control over the account, including consulting with respect to any particular transaction, you must give prior notice to
the Chief Compliance Officer. The account will then be subject to all provisions of the Code, and the exemptions in paragraph 3 of these procedures will be revoked.

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6.   Chief Compliance Officer Discretion. The Chief Compliance Officer has discretion to withhold
approval of blind trust or discretionary accounts arrangements, or at any time to impose additional or different conditions on such accounts.

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EXHIBIT C

CODE OF ETHICS CERTIFICATION FOR EMPLOYEES

I acknowledge that I
have received and read a copy of the Code of Ethics, as amended December 31, 2021, for Ariel Investment Trust, Ariel Investments, LLC, Ariel Distributors, LLC, Ariel Alternatives, LLC and Project Black Management Company, LLC. I understand my
responsibilities under the Code of Ethics and agree to comply with all of its terms and conditions. I further agree that my adherence to the Code of Ethics is a condition of employment with Ariel Investments, LLC, Ariel Alternatives, LLC, and/or
Project Black Management Company, LLC, as applicable. I will retain a copy of this Code of Ethics for future reference.

I further certify that I have complied
with the requirements of the Code of Ethics, as amended December 31, 2021, and I have disclosed or reported all personal securities transactions and accounts required to be disclosed or reported pursuant to such Code of Ethics.

CODE OF ETHICS CERTIFICATION FOR DISINTERESTED TRUSTEES,

DISINTERESTED DIRECTORS OR OUTSIDE BOARD MEMBERS

I acknowledge
that I have received and read a copy of the Code of Ethics, as amended December 31, 2021. I understand my responsibilities under the Code of Ethics and agree to comply with all of its terms and conditions. I will retain a copy of this Code of
Ethics for future reference.

I further certify that I have complied with the requirements of the Code of Ethics, as amended December 31, 2021, and I have
disclosed or reported all personal securities transactions required to be disclosed or reported pursuant to such Code of Ethics.