As filed with the Securities and Exchange Commission on June 16, 2015

Registration Statement No. 333-            

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

The Advisory Board Company

(Exact name of registrant as specified in its charter)

The Advisory Board Company Amended and Restated 2009 Stock Incentive Plan

(Full title of the plan)

Michael T. Kirshbaum

Chief Financial Officer

The Advisory Board Company

2445 M Street, NW

Washington, D.C. 20037

(Name and address of agent for service)

(202) 266-5600

(Telephone number, including area code, of agent for service)

Copies to:

Evan R. Farber

General Counsel and Corporate Secretary

The Advisory Board Company

2445 M Street, NW

Washington, D.C. 20037

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

CALCULATION OF REGISTRATION FEE

EXPLANATORY NOTE

In accordance with General Instruction E to Form S-8, this registration statement incorporates by reference the contents of Registration Statement No. 333-162032 on Form S-8 filed by The Advisory Board Company (the “Company”) on September 21, 2009, relating to shares of the Company’s common stock, par value $0.01 per share (the “Common Stock”), issuable pursuant to The Advisory Board Company 2009 Stock Incentive Plan (amended and restated as The Advisory Board Company Amended and Restated 2009 Stock Incentive Plan, the “Stock Incentive Plan”), Registration Statement No. 333-177006 on Form S-8 filed by the Company on September 26, 2011, relating to the registration of an additional 1,250,000 shares of Common Stock for issuance pursuant to the Stock Incentive Plan, and Registration Statement No. 333-192270 on Form S-8 filed by the Company on November 12, 2013, relating to the registration of an additional 2,125,000 shares of Common Stock for issuance pursuant to the Stock Incentive Plan. This registration statement, which is being filed to register an additional 5,179,486 shares of Common Stock for issuance pursuant to the Stock Incentive Plan, consists of the facing page, this page, other required information, and required opinions, consents and other exhibits.

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PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

The Company incorporates by reference herein the following documents filed by it with the Securities and Exchange Commission (the “SEC”) under Commission File Number 000-33283 pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”), other than any portion of such documents deemed to have been furnished and not filed in accordance with SEC rules:

In addition, the Company incorporates by reference all documents filed by it pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act (other than, in each case, documents or information deemed to have been furnished and not filed in accordance with SEC rules, unless specifically incorporated by reference in this registration statement) subsequent to the date hereof and prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold. All such incorporated documents shall be deemed to be a part of this registration statement from the date of filing of such documents.

Any statement contained in a document incorporated or deemed to be incorporated by reference into this registration statement shall be deemed to be modified or superseded for purposes of this registration statement to the extent that a statement contained in this registration statement or in any other subsequently filed document which also is or is deemed to be incorporated into this registration statement modifies or supersedes that statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this registration statement.

The legality of the shares of Common Stock being offered by this registration statement has been passed upon by Evan R. Farber, the Company’s General Counsel and Corporate Secretary. As of June 10, 2015, Mr. Farber beneficially owned 28,543 shares of Common Stock, including 24,999 shares issuable upon the exercise of stock options outstanding under employee benefit plans that were exercisable as of or within 60 days after such date, and held stock options outstanding under employee benefit plans to purchase an additional 66,166 shares of Common Stock and restricted stock units outstanding under employee benefit plans representing the right to acquire an additional 66,166 shares of Common Stock that are not vested and will not vest as of or within 60 days after such date.

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The Company herewith files or incorporates by reference the exhibits identified below:

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to section 13 or section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

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(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to section 13(a) or section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(h) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Washington, District of Columbia, on this 16^th day of June 2015.

POWER OF ATTORNEY

Each person whose signature appears below constitutes and appoints Robert W. Musslewhite, Michael T. Kirshbaum and Evan R. Farber, and each of them, as such person’s true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, from such person and in each person’s name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this registration statement or any registration statement relating to this registration statement under Rule 462 and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, granting unto such attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that such attorneys-in-fact and agents or any of them, or his, her or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities indicated and on the date indicated.

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EXHIBIT INDEX