Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
MASSARONI KENNETH M
   2. Issuer Name and Ticker or Trading Symbol
Seagate Technology plc [STX] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
EVP,General Counsel, CAO
(Last)
(First)
(Middle)
SEAGATE TECHNOLOGY PLC, 10200 S. DE ANZA BOULEVARD		 3. Date of Earliest Transaction (Month/Day/Year)
11/01/2012
(Street)

CUPERTINO, CA 95014		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Ordinary Shares 11/01/2012   M   10,000 A $ 3.345 46,554 D  
Ordinary Shares 11/01/2012   S(1)   10,000 D $ 27.2847 (1) 36,554 D  
Ordinary Shares 11/05/2012   S(2)   8,400 D $ 28.7221 (3) 28,154 D  

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
NQ Options $ 3.345 11/01/2012   M     10,000 09/11/2010(4) 03/06/2016 Ordinary Shares 10,000 $ 0 75,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
MASSARONI KENNETH M
SEAGATE TECHNOLOGY PLC
10200 S. DE ANZA BOULEVARD
CUPERTINO, CA 95014		       EVP,General Counsel, CAO  

Signatures

 /s/ Roberta S. Cohen by power-of-attorney   11/05/2012
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Shares sold under a 10b5-1 Trading Plan. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at sales prices ranging from $27.26 to $27.40, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
(2) Shares were sold to cover the tax liabilities resulting from the vesting on November 2, 2012 of 3,125 restricted shares which were awarded on September 12, 2008 and 17,000 performance unit shares which were awarded on September 12, 2011.
(3) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at sales prices ranging from $28.72 to $28.73, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
(4) Options granted to the Reporting Person under the Seagate Technology 2004 Stock Compensation Plan are subject to a four and a half year vesting schedule. One quarter of the option shares vested on September 11, 2010. Following continuous employment, the remaining shares vest proportionally monthly over the 36 months following September 11, 2010.
 
Remarks:
EXHIBIT INDEX
Exhibit 24 - Power of Attorney

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