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
OMB APPROVAL
OMB Number: 3235-0287
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
RE MARK
  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)
SVP & Chief Technical Officer
(Last)
(First)
(Middle)
SEAGATE TECHNOLOGY PLC, 10200 S. DE ANZA BOULEVARD
3. Date of Earliest Transaction (Month/Day/Year)
08/25/2015
(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 08/25/2015   M   4,167 A $ 11.065 68,325 D  
Ordinary Shares 08/25/2015   M   56,000 A $ 13.365 124,325 D  
Ordinary Shares 08/25/2015   M   16,667 A $ 3.345 140,992 D  
Ordinary Shares 08/25/2015   M   38,500 A $ 11.155 179,492 D  
Ordinary Shares 08/25/2015   S   115,334 D $ 48.7541 (1) 64,158 D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

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 Stock Options $ 11.065 08/25/2015   M     4,167 09/13/2011(2) 09/13/2017 Ordinary Shares 4,167 $ 0 0 D  
NQ Stock Options $ 13.365 08/25/2015   M     56,000 03/21/2012(3) 03/21/2018 Ordinary Shares 56,000 $ 0 0 D  
NQ Stock Options $ 3.345 08/25/2015   M     16,667 09/11/2010(4) 03/06/2016 Ordinary Shares 16,667 $ 0 0 D  
NQ Stock Options $ 11.155 08/25/2015   M     38,500 09/12/2012(5) 09/12/2018 Ordinary Shares 38,500 $ 0 12,300 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
RE MARK
SEAGATE TECHNOLOGY PLC
10200 S. DE ANZA BOULEVARD
CUPERTINO, CA 95014
      SVP & Chief Technical Officer  

Signatures

 /s/ Jolene Mendelsohn by power-of-attorney   08/27/2015
**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) These Ordinary Shares were sold in multiple transactions at sales prices ranging from $48.70 to $49.05, 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 ranges set forth in the footnote of this Form 4.
(2) Options granted to the Reporting Person under the Issuer's 2001 Stock Option Plan are subject to a four-year vesting schedule. One quarter of the option shares vested on September 13, 2011. The remaining option shares vested in equal monthly installments over the 36 months following September 13, 2011.
(3) Options granted to the Reporting Person under the Issuer's 2004 Stock Compensation Plan are subject to a four-year vesting schedule. One quarter of the option shares vested on March 21, 2012. The remaining option shares vested in equal monthly installments over the 36 months following March 21, 2012.
(4) Options granted to the Reporting Person under the Issuer's 2004 Stock Compensation Plan are subject to a four and one half-year vesting schedule. One quarter of the option shares vested on September 11, 2010. The remaining option shares vested in equal monthly installments over the 36 months following September 11, 2010.
(5) Options granted to the Reporting Person under the Issuer's 2004 Stock Compensation Plan are subject to a four-year vesting schedule. One quarter of the option shares vested on September 12, 2012. The remaining option shares vested in equal monthly installments over the 36 months following September 12, 2012.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.