Trinseo (TSE) DEFA14A Additional proxy soliciting materials

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.     )

Filed by the Registrant  x
Filed by a Party other than the Registrant  o
Check the appropriate box:
o	Preliminary Proxy Statement
o	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
o	Definitive Proxy Statement
x	Definitive Additional Materials
o	Soliciting Material under §240.14a-12
Trinseo S.A.
(Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement, if other than the Registrant)
Payment of Filing Fee (Check the appropriate box):
x	No fee required.
o	Fee computed on table below per Exchange Act Rules 14a-6(i)(1) and 0-11.
	(1)		Title of each class of securities to which transaction applies:
	(2)		Aggregate number of securities to which transaction applies:
	(3)		Per unit price or other underlying value of transaction computed pursuant to Exchange Act Rule 0-11 (set forth the amount on which the filing fee is calculated and state how it was determined):
	(4)		Proposed maximum aggregate value of transaction:
	(5)		Total fee paid:
o	Fee paid previously with preliminary materials.
o	Check box if any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid previously. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.
	(1)	Amount Previously Paid:
	(2)	Form, Schedule or Registration Statement No.:
	(3)	Filing Party:
	(4)	Date Filed:

*** Exercise Your Right to Vote *** Important Notice Regarding the Availability of Proxy Materials for the Shareholder Meeting to Be Held on June 21, 2016. TRINSEO S.A. You are receiving this communication because you hold shares in the company named above. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of TRINSEO S.A. 1000 CHESTERBROOK BLVD. SUITE 300 BERWYN, PA 19312 the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side). We encourage you to access and review all of the important information contained in the proxy materials before voting. proxy materials and voting instructions. E11134-P77930 See the reverse side of this notice to obtain Meeting Information Meeting Type:Annual General Meeting For holders as of:April 14, 2016 Date: June 21, 2016Time: 11:00 a.m. CEST Location: 4 rue du Fort Niedergrünewald BP 512/Quartier Européen Nord L-2015 Luxembourg Grand Duchy of Luxembourg

Before You Vote How to Access the Proxy Materials Have the information that is printed in the box marked by the arrow XXXX XXXX XXXX XXXX (located on the by the arrow XXXX XXXX XXXX XXXX (located on the following page) in the subject line. How To Vote Please Choose One of the Following Voting Methods marked by the arrow XXXX XXXX XXXX XXXX (located on the following page) available and follow the instructions. E11135-P77930 Vote In Person: Many shareholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares. Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a proxy card. Proxy Materials AAvvaaiillaabbllee ttooVVIEIEWWoorrRREECCEEIVIVEE: : NOTICE AND PROXY STATEMENT AND ANNUAL REPORT How to View Online: following page) and visit: www.proxyvote .com. How to Request and Receive a PAPER or E-MAIL Copy: If you want to receive a paper or e-mail copy of these documents, you must request one. There is NO charge for requesting a copy. Please choose one of the following methods to make your request: 1) BY INTERNET:www.proxyvote.com 2) BY TELEPHONE: 1-800-579-1639 3) BY E-MAIL*:sendmaterial@proxyvote.com * If requesting materials by e-mail, please send a blank e-mail with the information that is printed in the box marked Requests, instructions and other inquiries sent to this e-mail address will NOT be forwarded to your investment advisor. Please make the request as instructed above on or before June 7, 2016 to facilitate timely delivery.

The Boar d of Dir ecto rs r ecommends you vote FOR the following proposals: 1. To elect the three Class II directors specifically named in the proxy statement, each for a term of three years. Nominees: 6. To resolve on the allocation of the results of the year ended December 31, 2015. 1a. Christopher D. Pappas 1b. Stephen M. Zide 7. To approve the granting and discharge of the Company's directors and auditor for the performance of their respective duties during the year ended December 31, 2015. 1c. Felix S. Hauser 8. To ratify the appointment of PricewaterhouseCoopers Société cooperative to be our independent auditors for all statutory accounts required under Luxembourg law. To ratify the appointment of PricewaterhouseCoopers LLP to be our independent accounting firm. 2. To ratify the Board of Directors’ appointment of Stephen F. Thomas to fill a Class III vacancy, with a remaining term of one year. To ratify the Company’s directors’ compensation program. To approve, on an advisory basis, of the compensation paid by the Company to its named executive officers. 9. 3. 4. 10. To authorize the delegation to the Board the authorization to make repayments of equity at times and in amounts set by the Board in its discretion and within the limits of Luxembourg law. 5. To approve the Company’s annual accounts prepared in accordance with Luxembourg GAAP for the year ended December 31, 2015 (the “Luxembourg Annual Accounts”) and its consolidated financial statements prepared in accordance with U.S. GAAP including a footnote reconciliation of equity and net income IFRS for the year ended December 31, 2015 (the “Consolidated Accounts”) (together, the “Luxembourg Statutory Accounts”). 11. To authorize the Board to repurchase up to 4.5 million of its outstanding ordinary shares over the next two years. NOTE: Such other business as may properly come before the meeting or any adjournment thereof. E11136-P77930 Voting Items

E11137-P77930