As filed with the U.S. Securities and Exchange Commission on December 1, 2017

Registration No. 333-61366

811-10385

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

Pre-Effective Amendment No.                                ☐

Post-Effective Amendment No. 142 ☒

and/or

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940 ☐

Amendment No. 146 ☒

(Check appropriate box or boxes)

Pacific Funds Series Trust

(Exact Name of Registrant as Specified in Charter)

700 Newport Center Drive, P.O. Box 7500, Newport Beach, CA 92660

(Address of Principal Executive Offices) (Zip Code)

Registrant’s Telephone Number, including Area Code: (949) 219-3202

Audrey L. Cheng, Esq.

Pacific Life Insurance Company

700 Newport Center Drive

Newport Beach, CA 92660

(Name and Address of Agent for Service)

Copies to:

Anthony H. Zacharski, Esq.

Dechert LLP

90 State House Square

Hartford, CT 06103-3702

It is proposed that this filing will become effective (check appropriate box)

☒ immediately upon filing pursuant to paragraph (b)

☐ on (date) pursuant to paragraph (b)

☐ 60 days after filing pursuant to paragraph (a)(1)

☐ on (date) pursuant to paragraph (a)(1)

☐ 75 days after filing pursuant to paragraph (a)(2)

☐ on (date) pursuant to paragraph (a)(2) of rule 485.

If appropriate, check the following box:

☐ this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 (“Securities Act”) and the Investment Company Act of 1940, the Registrant has duly caused this Post-Effective Amendment No. 142 to its Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of Newport Beach, and in the State of California, on this 1^st day of December, 2017.

PACIFIC FUNDS SERIES TRUST
By:	/s/ Mark Karpe
	Mark Karpe
	Assistant Vice President and Counsel
	Pacific Life Insurance Company

Pursuant to the requirements of the Securities Act, this Post-Effective Amendment No. 142 to the Registration Statement of Pacific Funds Series Trust has been signed below by the following persons in the capacities and on the dates indicated.

James T. Morris*	Chairman of the Board and Trustee	December 1, 2017
Mary Ann Brown*	Chief Executive Officer	December 1, 2017
Frederick L. Blackmon*	Trustee	December 1, 2017
Lucie H. Moore*	Trustee	December 1, 2017
Gale K. Caruso*	Trustee	December 1, 2017
Nooruddin S. Veerjee*	Trustee	December 1, 2017
Paul A. Keller*	Trustee	December 1, 2017
Brian D. Klemens*	Vice President and Treasurer	December 1, 2017
	(Principal Financial and Accounting Officer)

*By:	/s/ Mark Karpe	December 1, 2017
	Mark Karpe
	as attorney-in-fact pursuant to power of attorney filed herewith

Pacific Funds Series Trust

Power of Attorney

The undersigned trustees and officers of Pacific Funds Series Trust (the “Trust”) hereby appoint Robin S. Yonis, Sharon A. Cheever, Jeffrey S. Puretz, Anthony Zacharski, Greg Larson, Mark Karpe, Audrey L. Cheng, Laurene E. MacElwee, Howard T. Hirakawa, and Carleton J. Muench each individually as their true and lawful attorneys-in-fact (“attorneys”), in all capacities, to execute in their name and file any and all registration statements, including registration statements on Form N-14, proxy statements, exemptive applications, no-action letter requests, shareholder reports and other regulatory filings made applicable to the Trust and each series of the Trust, and any amendments, exhibits, or supplements thereto, and any instruments necessary or desirable in connection therewith as are required to enable the Trust to comply with provisions of the Securities Act of 1933, as amended, and/or the Securities Exchange Act of 1934, as amended, and/or the Investment Company Act of 1940, as amended, and all requirements and regulations of the Securities and Exchange Commission (“SEC”) in connection with the offer of the shares of beneficial interest of the Trust and each series of the Trust, and to file the same, with other documents in connection herewith, with the SEC, any state securities regulator, any self-regulatory organization or any other governmental or official body (including, without limitation, agencies, commissions and authorities). The undersigned grant to said attorneys full authority to do every act necessary to be done in order to effectuate the same as fully, to all intents and purposes, as he or she could do if personally present, thereby ratifying all that said attorneys may lawfully do or cause to be done by virtue hereof. This Power of Attorney hereby terminates and replaces all other previously executed Power of Attorneys for the Trust related to the above.

The undersigned trustees and officers of Pacific Funds Series Trust hereby execute this Power of Attorney effective the 1^st day of January, 2017.

NAME	TITLE
/s/ James T. Morris	Chairman and Trustee
James T. Morris
/s/ Frederick L. Blackmon	Trustee
Frederick L. Blackmon
/s/ Gale K. Caruso	Trustee
Gale K. Caruso
/s/ Paul A. Keller	Trustee
Paul A. Keller
/s/ Lucie H. Moore	Trustee
Lucie H. Moore
/s/ Nooruddin S. Veerjee	Trustee
Nooruddin S. Veerjee
/s/ Mary Ann Brown	Chief Executive Officer
Mary Ann Brown
/s/ Brian D. Klemens	Vice President and Treasurer
Brian D. Klemens

EXHIBIT INDEX

Title of Exhibit	Exhibit No.
XBRL Instance Document	Ex-101.ins
XBRL Taxonomy Extension Schema Document	Ex-101.sch
XBRL Taxonomy Extension Calculation Linkbase Document	Ex-101.cal
XBRL Taxonomy Extension Labels Linkbase	Ex-101.lab
XBRL Taxonomy Extension Presentation Linkbase Document	Ex-101.pre
XBRL Taxonomy Extension Definition Linkbase	Ex-101.def