As filed with the Securities and Exchange Commission on May 6, 2015.

Registration No. 333-        

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

TALLGRASS ENERGY GP, LP

(Exact name of Registrant as specified in its charter)

4200 W. 115th Street, Suite 350

Leawood, Kansas 66211

(913) 928-6060

(Address, including zip code, and telephone number, including area code, of Registrant’s principal executive offices)

George E. Rider

4200 W. 115th Street, Suite 350

Leawood, Kansas 66211

(913) 928-6060

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public:

As soon as practicable after the effective date of this Registration Statement.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box.  ¨

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  x    333-202258

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

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

The registration statement shall become effective upon filing with the Commission in accordance with Rule 462 (b) under the Securities Act.

EXPLANATORY NOTE AND INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

Pursuant to Rule 462(b) under the Securities Act of 1933, as amended, Tallgrass Energy GP, LP (“Registrant”) is filing this registration statement with the Securities and Exchange Commission (“Commission”). This registration statement relates to the public offering of securities contemplated by the registration statement on Form S-1, as amended (File No. 333-202258) (“Amended Registration Statement”), and which the Commission declared effective on May 6, 2015.

The Registrant is filing this registration statement for the sole purpose of increasing the aggregate number of shares of Class A shares offered by the Registrant by 7,117,350 shares. The additional securities that are being registered for issuance and sale are in an amount and at a price that together represent no more than 20% of the maximum aggregate offering price set forth in the Calculation of Registration Fee table contained in the Amended Registration Statement. The information set forth in the Amended Registration Statement and all exhibits to the Amended Registration Statement are hereby incorporated by reference in this filing.

The required opinions and consents are listed on the Exhibit Index attached hereto and filed herewith.

The Registrant hereby (i) undertakes to pay the Commission the filing fee set forth on the cover page of this Rule 462(b) Registration Statement by a wire transfer of such amount as soon as practicable (but no later than the close of business on May 7, 2015) and (ii) certifies that it has sufficient funds in the relevant account to cover the amount of such filing fee.

Signatures

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Leawood, State of Kansas, on May 6, 2015.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and the dates indicated.

EXHIBIT INDEX