UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D/A

Under the Securities Exchange Act of 1934

(Amendment No. 5)*

Platform Specialty Products Corporation

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

72766Q 105 (Common Stock)

(CUSIP Number)

Mariposa Acquisition, LLC

5200 Blue Lagoon Drive, Suite 855

Miami, Florida 33126

Attn: Martin E. Franklin

(561) 447-2510

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

September 16, 2016

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of § 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box  ¨.

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7(b) for other parties to whom copies are to be sent.

The information required on 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 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).

SCHEDULE 13D

SCHEDULE 13D

SCHEDULE 13D

This Amendment No. 5 (this “Amendment”) amends the Statement on Schedule 13D, filed with the Commission on January 27, 2014 (as amended by Amendment No. 1, filed on March 14, 2014, Amendment No. 2, filed on October 7, 2014, Amendment No. 3 filed on January 2, 2015 and Amendment No. 4 filed on March 20, 2015, the “Statement”), with respect to the common stock, par value $0.01 per share (the “Common Stock”), of Platform Specialty Products Corporation, a Delaware corporation (the “Issuer”). The principal executive offices of the Issuer are located at 1450 Centrepark Blvd, Suite 210, West Palm Beach, Florida 33401. Unless specifically amended hereby, the disclosure set forth in the Statement shall remain unchanged. Capitalized terms used but not otherwise defined in this Amendment shall have the meanings set forth in the Statement.

Item 4 of the Schedule 13D is hereby amended by the addition of the following:

On September 15, 2016, the Issuer entered into an underwriting agreement (the “Underwriting Agreement”) with Credit Suisse Securities (USA) LLC, as representative of the several underwriters named in Schedule I thereto (collectively, the “Underwriters”) relating to the underwritten public offering (the “Offering”) of 42,424,242 shares of Common Stock, at a public offering price of $8.25 per share. In addition, the Issuer granted the Underwriters a 30-day option to purchase up to 6,363,636 additional shares of Common Stock (the “Over-Allotment Option”). The Issuer expects the Offering to close on or about September 21, 2016, subject to the satisfaction of various customary closing conditions. On September 16, 2016, the Trust agreed to purchase 1,050,000 shares of Common Stock from the Underwriters in connection with the Offering at the public offering price of $8.25 per share.

Paragraphs (a) - (c) of Item 5 of the Statement are hereby amended and restated in their entirety as follows:

(a) - (b) As of the date hereof, each of Franklin, Mariposa and the Trust have shared power to vote, or to direct the vote, and shared power to dispose, or to direct the disposition of, an aggregate of 14,190,546, 11,509,987 and 13,947,436 shares of Common Stock (and shares convertible into Common Stock within 60 days), respectively. These amounts consist of (i) 2,437,449 shares held directly by the Trust, (ii) 243,110 shares of Common Stock held indirectly by Franklin through RSMA LLC, (iii) 10,449,987 shares of Common Stock held directly by Mariposa, and (iv) 1,060,000 shares of Series A Preferred Stock held directly by Mariposa that are convertible at any time at the option of the holder into the same number of shares of Common Stock. In the aggregate, such 14,190,546, 11,509,987 and 13,947,436 shares of Common Stock represent approximately 5.1%, 4.1% and 5.0%, respectively, of all outstanding shares of Common Stock (calculated based on 278,420,786 shares of Common Stock expected to be outstanding immediately following the closing of the Offering, assuming (i) exercise of the Over-Allotment Option by the Underwriters and (ii) conversion of the shares of Series A Preferred Stock, but without including any

conversion of shares of Series A Preferred Stock held by any other person). Franklin owns, directly or indirectly, 61.32% of Mariposa, representing 6,407,932 shares of Common Stock and 649,992 shares of Series A Preferred Stock.

(c) On September 16, 2016, the Trust agreed to purchase 1,050,000 shares of Common Stock from the Underwriters in connection with the Offering at the public offering price of $8.25 per share.

Item 6 of the Schedule 13D is hereby amended by the addition of the following:

Franklin has agreed that, prior to November 14, 2016, subject to certain limited exceptions, he will not directly or indirectly, without the prior written consent of Credit Suisse Securities (USA) LLC, (1) offer for sale, sell, pledge, or otherwise dispose of (or enter into any transaction or device that is designed to, or could be expected to, result in the disposition by any person at any time in the future of) any shares of Common Stock (including, without limitation, shares of Common Stock that may be deemed to be beneficially owned by him in accordance with the rules and regulations of the SEC and shares of Common Stock that may be issued upon exercise of any options or warrants) or securities convertible into or exercisable or exchangeable for Common Stock, or sell or grant options, rights or warrants with respect to any shares of common stock or securities convertible into or exchangeable for common stock, (2) enter into any swap or other derivatives transaction that transfers to another, in whole or in part, any of the economic benefits or risks of ownership of shares of Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or other securities, in cash or otherwise, (3) make any demand for or exercise any right or file or cause to be filed a registration statement, including any amendments thereto, with respect to the registration of any shares of Common Stock or securities convertible, exercisable or exchangeable into common stock or any of our other securities, or (4) publicly disclose the intention to do any of the foregoing.

SIGNATURE

After reasonable inquiry and to the best of each of the Reporting Person’s knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

LOCK-UP LETTER AGREEMENT

CREDIT SUISSE SECURITIES (USA) LLC

c/o Credit Suisse Securities (USA) LLC Eleven

Madison Avenue

New York, New York 10010 Ladies

and Gentlemen:

The undersigned understands that you and certain other firms (the “Underwriters”) propose to enter into an Underwriting Agreement dated September 15, 2016 (the “Underwriting Agreement”) providing for the purchase by the Underwriters of shares (the “Stock”) of Common Stock, par value $0.01 per share (the “Common Stock”), of Platform Specialty Products Corporation, a Delaware corporation (the “Company”), and that the Underwriters propose to reoffer the Stock to the public (the “Offering”).

In consideration of the execution of the Underwriting Agreement by the Underwriters, and for other good and valuable consideration, the undersigned hereby irrevocably agrees that, without the prior written consent of Credit Suisse Securities (USA) LLC, on behalf of the Underwriters, the undersigned will not, directly or indirectly, (1) offer for sale, sell, pledge, or otherwise dispose of (or enter into any transaction or device that is designed to, or could be expected to, result in the disposition by any person at any time in the future of) any shares of Common Stock (including, without limitation, shares of Common Stock that may be deemed to be beneficially owned by the undersigned in accordance with the rules and regulations of the Securities and Exchange Commission and shares of Common Stock that may be issued upon exercise of any options or warrants) or securities convertible into or exercisable or exchangeable for Common Stock, (2) enter into any swap or other derivatives transaction that transfers to another, in whole or in part, any of the economic benefits or risks of ownership of shares of Common Stock, whether any such transaction described in clause or (2) above is to be settled by delivery of Common Stock or other securities, in cash or otherwise, (3) make any demand for or exercise any right or cause to be filed a registration statement, including any amendments thereto, with respect to the registration of any shares of Common Stock or securities convertible into or exercisable or exchangeable for Common Stock or any other securities of the Company, or (4) publicly disclose the intention to do any of the foregoing for a period commencing on the date hereof and ending on the 60th day after the date of the Prospectus relating to the Offering (such 60-day period, the “Lock-Up Period”).

The foregoing paragraph shall not apply to:

(a) transactions relating to shares of Common Stock or other securities acquired in open market transactions after the completion of the Offering;

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(b) transfers of shares of Common Stock or any security convertible into or exercisable or exchangeable for Stock as a bona fide gift;

(c) in the case of a non-natural person, distributions of shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock to limited partners, members or stockholders of the undersigned;

(d) in the case of a natural person, transfers of shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock by will or intestate succession or to any trust or entity for the direct or indirect benefit of such person or any member of the immediate family of the undersigned;

(e) the entry by the undersigned into a trading plan established in accordance with Rule 10b5-1 under the Securities Exchange Act of 1934, as amended, provided that sales under any such plan may not occur during the period in which the restrictions otherwise imposed by this agreement apply; or

(f) in the case of a non-natural person, transfers of shares of Common Stock to any wholly-owned subsidiary of the undersigned (including any corporation, partnership, limited liability company or other entity that is directly or indirectly owned by the undersigned) or to the parent corporation of the undersigned or any wholly-owned subsidiary of such parent corporation;

provided that (i) in the case of any transfer or distribution pursuant to clauses (b), (c), (d) and (f), such transfer shall not involve a disposition for value and each donee, distributee or transferee shall sign and deliver a lock-up letter substantially in the form of this letter and (ii) in the case of any transfer or distribution pursuant to clauses (b), (d) and (f), no filing under Section 16(a) of the Exchange Act, reporting a reduction in beneficial ownership of shares of Common Stock, shall be required or shall be voluntarily made during the Lock-Up Period.

In furtherance of the foregoing, the Company and its transfer agent are hereby authorized to decline to make any transfer of securities if such transfer would constitute a violation or breach of this Lock-Up Letter Agreement.

It is understood that, if the Company notifies the Underwriters that it does not intend to proceed with the Offering, if the Underwriting Agreement does not become effective, or if the Underwriting Agreement (other than the provisions thereof which survive termination) shall terminate or be terminated prior to payment for and delivery of the Stock, the undersigned will be released from its obligations under this Lock-Up Letter Agreement.

The undersigned understands that the Company and the Underwriters will proceed with the Offering in reliance on this Lock-Up Letter Agreement.

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Whether or not the Offering actually occurs depends on a number of factors, including market conditions. Any Offering will only be made pursuant to an Underwriting Agreement, the terms of which are subject to negotiation between the Company and the Underwriters.

[Signature page follows]

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The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Lock-Up Letter Agreement and that, upon request, the undersigned will execute any additional documents necessary in connection with the enforcement hereof. Any obligations of the undersigned shall be binding upon the heirs, personal representatives, successors and assigns of the undersigned.

Dated: September 14, 2016