UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 14A

(RULE 14a-101)

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No.    )

Filed by the Registrant  ☒                            Filed by a Party other than the Registrant  ☐

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☐	Preliminary Proxy Statement
☐	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
☐	Definitive Proxy Statement
☒	Definitive Additional Materials
☐	Soliciting Material Pursuant to Section 240.14a-12
WESCO INTERNATIONAL, INC.
(Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement)
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*** Exercise Your Right to Vote ***

Important Notice Regarding the Availability of Proxy Materials for the

Shareholder Meeting to Be Held on May 31, 2017

	WESCO INTERNATIONAL, INC.		Meeting Information
			Meeting Type: Annual Meeting
			For holders as of: April 07, 2017
			Date: May 31, 2017	Time: 5:00 PM EDT
			Location:   Hyatt Regency Pittsburgh International Airport
			1111 Airport Boulevard,                       Pittsburgh, PA 15231
		You are receiving this communication because you hold shares in the above named company. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of 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.
			See the reverse side of this notice to obtain proxy materials and voting instructions.

—  Before You Vote   —

How to Access the Proxy Materials

Proxy Materials Available to VIEW or RECEIVE:
1. Notice and Proxy Statement         2. Annual Report How to View Online: Have the information that is printed in the box marked by the arrow       (located on the 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 by the arrow     (located on the following page) in the subject line. 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 May 17, 2017 to facilitate timely delivery.

—  How To Vote   —

Please Choose One of the Following Voting Methods

Vote In Person: If you choose to vote these shares in person at the meeting, you must request a “legal proxy.” To do so, please follow the instructions at www.proxyvote.com or request a paper copy of the materials, which will contain the appropriate instructions. 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. Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box marked by the arrow         available and follow the instructions. Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a voting instruction form.

Voting items

	The Board of Directors recommends that you vote FOR the following:
	1.	Elect eight Directors for a one-year term expiring in 2018.
		Nominees
	01	Sandra Beach Lin              02   John J. Engel                  03   Matthew J. Espe          04   Bobby J. Griffin          05   John K. Morgan
	06	Steven A. Raymund           07   James L. Singleton         08   Lynn M. Utter
	The Board of Directors recommends you vote FOR the following proposal(s):
	2.	Approve, on an advisory basis, the compensation of the Company’s named executive officers.
	The Board of Directors recommends you vote 1 YEAR on the following proposal:
	3.	Approve, on an advisory basis, the frequency of an advisory vote on executive compensation.
	The Board of Directors recommends you vote FOR the following proposal(s):
	4.	Approve the renewal and restatement of the WESCO International, Inc. 1999 Long-Term Incentive Plan.
	5.	Ratify the appointment of PricewaterhouseCoopers LLP as our independent registered public accounting firm for the year ending December 31, 2017.
	NOTE: Such other business as may properly come before the meeting or any adjournment thereof.

	Voting Instructions