UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.     )

ZAYO GROUP HOLDINGS, INC.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

98919V105

(CUSIP Number)

December 31, 2014

(Date of Event which Requires filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

¨ Rule 13d-1(b)

¨ Rule 13d-1(c)

x Rule 13d-1(d)

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Zayo Group Holdings, Inc. (the “Issuer”).

1805 29th Street, Suite 2050

Boulder, CO 80301

Each of the following is hereinafter individually referred to as a “Reporting Person” and collectively as the “Reporting Persons.” This statement is filed on behalf of:

Battery Ventures VII, L.P.

Battery Investment Partners VII, LLC

Battery Ventures VIII, L.P.

Battery Partners VII, LLC

Battery Partners VIII, LLC

Battery Management Corp.

Thomas J. Crotty

Richard D. Frisbie

Kenneth P. Lawler

R. David Tabors

Scott R. Tobin

Neeraj Agrawal

Michael M. Brown

Roger H. Lee

The business address of each of the Reporting Persons is c/o Battery Ventures, One Marina Park Drive, Suite 1100, Boston, MA 02210.

Common stock, $0.001 par value per share (“Common Stock”).

98919V105

Not applicable.

Ownership (a-c)

The ownership information presented below represents beneficial ownership of Common Stock of the Issuer as of December 31, 2014, based upon 239,008,679 shares of the Issuer’s Common Stock outstanding as of November 10, 2014.

Consists of (i) 10,648,920 shares held of record by Battery Ventures VII, L.P. (“Battery Ventures VII”); (ii) 203,980 shares held of record by Battery Investment Partners VII, LLC (“BIPVII”); and (iii) 3,398,702 shares held of record by Battery Ventures VIII, L.P. (“Battery Ventures VIII”) (collectively, the “Battery Shareholders”). Battery Partners VII, LLC (“BPVII”) is the sole general partner of Battery Ventures VII and the sole managing member of BIPVII. BPVII’s investment adviser is Battery Management Corp. (“BMC”). Thomas J. Crotty, Richard D. Frisbie, Kenneth P. Lawler, R. David Tabors and Scott R. Tobin are the managing members of BPVII and are officers of BMC, and collectively share voting and dispositive authority over the securities held by held by Battery Ventures VII and BIPVII. Battery Partners VIII, LLC (“BPVIII”) is the sole general partner of Battery Ventures VIII. BPVIII’s investment adviser is BMC. Neeraj Agrawal, Michael M. Brown, Thomas J. Crotty, Richard D. Frisbie, Kenneth P. Lawler, R. David Tabors, Scott R. Tobin and Roger H. Lee are the managing members of BPVIII and are officers of BMC, and they collectively share voting and dispositive authority over the securities held by Battery Ventures VIII. Each of the foregoing entities and individuals disclaims beneficial ownership of the shares held of record by the Battery Shareholders.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: February 12, 2015

LIST OF EXHIBITS

Exhibit 24.1

POWER OF ATTORNEY

KNOW ALL MEN AND WOMEN BY THESE PRESENTS, that each person whose signature appears below (each, a “Reporting Person”) hereby constitutes and appoints Thomas J. Crotty, Christopher Hanson, Morgan M. Jones and Christopher Schiavo (collectively, the “Authorized Signatories”), and each of them, with full power to act without the other, such Reporting Person’s true and lawful attorney-in-fact, with full power of substitution, to sign any and all reports, instruments, certificates and documents that may be necessary, desirable or appropriate to be executed by such Reporting Person in any and all capacities, including but not limited to his capacity as a managing member of Battery Partners VII, LLC, with respect to such Reporting Person’s ownership of, or transactions in, securities of any entity whose securities are beneficially owned (directly or indirectly) by such Reporting Person, as a result of his relationship with the foregoing entity or with Battery Ventures VII, L.P. or Battery Investment Partners VII, LLC (collectively, the “Companies”), pursuant to Section 13 or Section 16 of the Securities Exchange Act of 1934, as amended (together with any and all regulations promulgated thereunder, the “Exchange Act”) (collectively, the “Reports”), and to file the same, with all exhibits thereto, and any other documents in connection therewith, with the Securities and Exchange Commission, and with any other entity when and if such is mandated by the Act or the Exchange Act or by the By-laws of the National Association of Securities Dealers, Inc., granting unto said attorneys-in-fact full power and authority to do and perform each and every act and thing necessary, desirable or appropriate, fully to all intents and purposes as such Reporting Person might or could do in person, thereby ratifying and confirming all that said Authorized Signatories, or their substitutes, may lawfully do or cause to be done by virtue hereof.

The authority granted pursuant to this Power of Attorney shall continue with respect to each Reporting Person until such Reporting Person is no longer required to file any Reports with respect to the Reporting Person’s ownership of, or transactions in, the securities of the Companies, unless earlier revoked in writing. Each Reporting Person acknowledges that the Authorized Signatories are not assuming any of the Reporting Person’s responsibilities to comply with the Act or the Exchange Act.

IN WITNESS WHEREOF, this Power of Attorney has been signed as of the 17th day of February, 2006.

Exhibit 24.2

POWER OF ATTORNEY

KNOW ALL MEN AND WOMEN BY THESE PRESENTS, that the person whose signature appears below (a “Reporting Person”) hereby constitutes and appoints Thomas J. Crotty, Christopher Hanson, Morgan M. Jones and Christopher Schiavo (collectively, the “Authorized Signatories”), and each of them, with full power to act without the other, such Reporting Person’s true and lawful attorney-in-fact, with full power of substitution, to sign any and all reports, instruments, certificates and documents that may be necessary, desirable or appropriate to be executed by such Reporting Person in any and all capacities, including but not limited to his capacity as a managing member of Battery Partners VII, LLC, with respect to such Reporting Person’s ownership of, or transactions in, securities of any entity whose securities are beneficially owned (directly or indirectly) by such Reporting Person, as a result of his relationship with the foregoing entity or with Battery Ventures VII, L.P. or Battery Investment Partners VII, LLC (collectively, the “Companies”), pursuant to Section 13 or Section 16 of the Securities Exchange Act of 1934, as amended (together with any and all regulations promulgated thereunder, the “Exchange Act”) (collectively, the “Reports”), and to file the same, with all exhibits thereto, and any other documents in connection therewith, with the Securities and Exchange Commission, and with any other entity when and if such is mandated by the Act or the Exchange Act or by the By-laws of the National Association of Securities Dealers, Inc., granting unto said attorneys-in-fact full power and authority to do and perform each and every act and thing necessary, desirable or appropriate, fully to all intents and purposes as such Reporting Person might or could do in person, thereby ratifying and confirming all that said Authorized Signatories, or their substitutes, may lawfully do or cause to be done by virtue hereof.

The authority granted pursuant to this Power of Attorney shall continue with respect to such Reporting Person until such Reporting Person is no longer required to file any Reports with respect to the Reporting Person’s ownership of, or transactions in, the securities of the Companies, unless earlier revoked in writing. Such Reporting Person acknowledges that the Authorized Signatories are not assuming any of the Reporting Person’s responsibilities to comply with the Act or the Exchange Act.

IN WITNESS WHEREOF, this Power of Attorney has been signed as of the          day of             , 2008.

Exhibit 24.3

POWER OF ATTORNEY

KNOW ALL MEN AND WOMEN BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Christopher Hanson and Christopher Schiavo and any one of them, with full power to act without the other, his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for the undersigned and in the undersigned’s name, place, and stead, until revoked in writing, to sign any and all instruments, certificates and documents that may be necessary, desirable or appropriate to be executed in any and all capacities, including but not limited to his capacity as a managing member, member, former member or other beneficial owner of Battery Partners VIII, LLC, or in his capacity as a managing member, member, former member or other beneficial owner of any entity formed to serve as a general partner or managing member of any Alternative Fund formed pursuant to the terms and provisions of the Limited Partnership Agreement of Battery Ventures VIII, L.P. dated as of July 2, 2007 (each such fund, an “Alternative Fund), with respect to securities held by such signatory as a result of his relationship with any of the foregoing entities or with Battery Ventures VIII, L.P., or any Alternative Fund, pursuant to the Securities Act of 1933, as amended (together with the implementing regulations thereto, the “Securities Act”) or the Securities Exchange Act of 1934, as amended (together with the implementing regulations thereto, the “Exchange Act”), and to file the same, with all exhibits thereto, and any other documents in connection therewith, with the Securities and Exchange Commission, and with any other entity when and if such is mandated by the Securities Act, the Exchange Act or by the Financial Industry Regulatory Authority, granting unto said attorneys-in-fact full power and authority to do and perform each and every act and thing necessary, desirable or appropriate, fully to all intents and purposes as he might or could do in person, thereby ratifying and confirming all that said attorneys-in-fact, or their substitutes, may lawfully do or cause to be done by virtue hereof.

The authority granted pursuant to this Power of Attorney shall continue with respect to each Reporting Person until such Reporting Person is no longer required to file any Reports with respect to the Reporting Person’s ownership of, or transactions in, the securities of the Companies, unless earlier revoked in writing. Each Reporting Person acknowledges that the Authorized Signatories are not assuming any of the Reporting Person’s responsibilities to comply with the Act or the Exchange Act.

IN WITNESS WHEREOF, this Power of Attorney has been signed as of the 19th day of May, 2008.

Exhibit 99

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree to the joint filing with each other on behalf of each of them of such a statement on Schedule 13G with respect to the common stock beneficially owned by each of them of Zayo Group Holdings, Inc. This Joint Filing Agreement shall be included as an Exhibit to such Schedule 13G.

IN WITNESS WHEREOF, the undersigned hereby execute this Joint Filing Agreement as of the 12th day of February, 2015.