2018 Annual Report Proxy Statement and Form 10-K FORWARD-LOOKING STATEMENT: This Annual Report contains forward-looking statements that are subject to safe harbors under the Securities Act of 1933, as amended and the Securities Exchange Act of 1934, as amended. Statements that refer to projections of our future financial performance, anticipated growth and trends in our businesses and in our industries, the actions we intend to take as part of our new strategy and the expected impact thereof, the anticipatedimpactsof our acquisitions and restructurings, our intent to pay quarterly cash dividends in the future, and other characterizations of future events or circumstances are forward-looking statements. These statements are only predictions, based on our current expectations about future events and may not prove to be accurate. We do not undertake any obligation to update these forward-looking statements to reflect events occurring or circumstances arising after the date of this report. These forward-looking statements involve risks and uncertainties, and our actual results, performance, or achievements could differ materially from those expressed or implied by the forward-looking statements on the basis of several factors, including those that we discuss in the “Risk Factors” section and throughout our 2018 Form 10-K, which is included in this Annual Report. We encourage you to read that section carefully. 350 Ellis Street Mountain View, California 94043 NOTICE OF 2018 ANNUAL MEETING OF STOCKHOLDERS to be held on: December 3, 2018 9:00 a.m. Pacific Time Dear Stockholder: You are cordially invited to attend our 2018 Annual Meeting of Stockholders (the “Annual Meeting”), which will be held at 9:00 a.m. (Pacific Time) on Monday, December 3, 2018. This year’s meeting will again be completely virtual and conducted via live webcast. You will be able to attend the Annual Meeting online and submit your questions prior to or during the meeting by visit- ing www.virtualshareholdermeeting.com/SYMC2018. You will also be able to vote your shares electronically at the Annual Meeting. We are excited to embrace the latest technology to provide expanded access, improved communication and cost savings for our stockholders. Hosting a virtual meeting enables increased stockholder attendance and participation since stockholders can participate from any location around the world. In addition, the online format will allow us to communicate more effectively with you via a pre-meeting forum that you can enter by visiting www.virtualshareholdermeeting.com/SYMC2018 and submit questions in advance of the Annual Meeting. For your convenience, we are also pleased to offer a re-playable webcast of the Annual Meeting at investor.symantec.com. We are holding the Annual Meeting for the following purposes, which are more fully described in the proxy statement: 1. To elect the eleven nominees named in the proxy statement to Symantec’s Board of Directors; 2. To ratify the appointment of KPMG LLP as Symantec’s independent registered public accounting firm for the 2019 fiscal year; 3. To approve amendments to our 2013 Equity Incentive Plan, as amended, to increase the number of shares authorized for issuance thereunder by 12,000,000 shares and to approve additional amendments thereto; 4. To approve amendments to our 2008 Employee Stock Purchase Plan, as amended, to extend the term by an addi- tional ten years; 5. To hold an advisory vote to approve executive compensation; and 6. To transact such other business as may properly come before the meeting or any adjournment or postponement thereof. On or about October 29, 2018, we expect to send to our stockholders our proxy materials, including our proxy statement and our annual report, and instructions on how to vote through the Internet or by telephone. Only stockholders of record as of the close of business on October 5, 2018 are entitled to notice of, and vote at, the Annual Meeting or any postponement or adjournment thereof. A list of stockholders entitled to vote will be available for inspection at our offices for ten days prior to the Annual Meeting. If you would like to view this stockholder list, please contact Investor Relations at (650) 527-8020. Your vote is very important. Whether or not you plan to virtually attend the Annual Meeting, please vote at your earliest convenience by following the instructions in the proxy card you received in the mail. You may revoke your proxy at any time before it is voted. Please refer to the “2018 Annual Meeting of Stockholders Meeting Information” section of the proxy statement for additional information. BY ORDER OF THE BOARD OF DIRECTORS SCOTT C. TAYLOR Executive Vice President, General Counsel and Secretary Mountain View, California October 29, 2018 IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE STOCKHOLDER MEETINGTOBEHELD ON DECEMBER 3, 2018. The proxy statement and Symantec’s Form 10-K for the 2018 fiscal year are available at http://investor.symantec.com/About/Investors/financial-information/Annual-Reports/default.aspx. [THIS PAGE INTENTIONALLY LEFT BLANK] TABLE OF CONTENTS Page PROXY SUMMARY ............................................................... 1 CORPORATE GOVERNANCE ...................................................... 8 Corporate Governance Guidelines .................................................. 8 Code of Conduct and Code of Ethics ................................................ 8 Policy Against Short-Selling, Hedging and Pledging Symantec Securities .................. 8 Stock Ownership Guidelines ...................................................... 8 Stockholder Engagement ......................................................... 9 Majority Vote Standard and Director Resignation Policy ................................ 9 Proxy Access ................................................................... 9 Board Leadership Structure ....................................................... 10 Board Independence ............................................................. 10 Change in Director Occupation .................................................... 10 Board and Committee Effectiveness ................................................ 10 Board’s Role in Risk Oversight ..................................................... 11 Board’s Role in Oversight of Company Strategy ....................................... 11 Board’s Role in Oversight of Human Capital Management .............................. 12 Outside Advisors ................................................................ 12 Board Structure and Meetings ..................................................... 12 Executive Sessions .............................................................. 13 Succession Planning ............................................................. 13 Attendance of Board Members at Annual Meetings .................................... 13 THE BOARD AND ITS COMMITTEES ................................................ 14 Audit Committee ................................................................ 14 Compensation and Leadership Development Committee ............................... 15 Nominating and Governance Committee ............................................. 16 DIRECTOR NOMINATIONS AND COMMUNICATION WITH DIRECTORS .................. 17 Criteria for Nomination to the Board ................................................ 17 Process for Identifying and Evaluating Nominees ..................................... 18 Stockholder Proposals for Nominees ................................................ 18 Contacting the Board of Directors .................................................. 19 PROPOSAL NO. 1 ELECTION OF DIRECTORS ....................................... 20 Nominees for Director ............................................................ 20 Agreement with Starboard Value LP ................................................ 32 Summary of Director Qualifications and Experience ................................... 32 Fiscal 2018 Director Compensation ................................................. 34 PROPOSAL NO. 2 RATIFICATION OF APPOINTMENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM ..................................................... 35 Principal Accountant Fees and Services ............................................. 35 Policy on Audit Committee Pre-Approval of Audit and Permissible Non-Audit Services of Independent Registered Public Accounting Firm .................................... 35 PROPOSAL NO. 3 AMENDMENTS TO 2013 EQUITY INCENTIVE PLAN, AS AMENDED ..... 37 Promotion of Good Compensation Practices ......................................... 37 Planned Frequency of Share Requests .............................................. 37 Share Request Background ....................................................... 38 Non-Employee Director Compensation Limit ......................................... 38 i Page Equity Plan Philosophy ........................................................... 39 Plan History .................................................................... 39 Plan History — Burn Rate ......................................................... 40 Summary of our 2013 Equity Incentive Plan, as Amended .............................. 42 Summary of Federal Income Tax Consequences of Awards Granted under the 2013 Equity Incentive Plan, as Amended ..................................................... 44 ERISA Information ............................................................... 45 Accounting Treatment ...........................................................