Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF 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 *
  DEHAAN DOUGLAS J
 2. Date of Event Requiring Statement (Month/Day/Year)
09/18/2012		 3. Issuer Name and Ticker or Trading Symbol
Seagate Technology plc [STX]
(Last)
(First)
(Middle)
SEAGATE TECHNOLOGY PLC, 920 DISC DRIVE		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
General Manager, Samsung HDD
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

SCOTTS VALLEY, CA 95066		 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 Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Ordinary Shares 30,953.404 (1) (2) (3)
D
 
Ordinary Shares 91,707
I
Gayle H. Dehaan Trust U/A/D 11-29-2005
Ordinary Shares 1,018
I
Gayle H. DeHaan Custodian for Taylor J DeHaan
Ordinary Shares 1,018
I
Gayle H. DeHaan Custodian for Bradley R DeHaan

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
NQ Stock Options 09/11/2010(4) 03/06/2016 Ordinary Shares 108,334 $ 3.345 D  
NQ Stock Options 09/13/2011(5) 09/13/2017 Ordinary Shares 22,136 $ 11.065 D  
NQ Stock Options 09/12/2012(6) 09/12/2018 Ordinary Shares 63,400 $ 11.155 D  
NQ Stock Options 09/10/2013(7) 09/10/2019 Ordinary Shares 18,030 $ 29.87 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
DEHAAN DOUGLAS J
SEAGATE TECHNOLOGY PLC
920 DISC DRIVE
SCOTTS VALLEY, CA 95066		       General Manager, Samsung HDD  

Signatures

/s/ Roberta S. Cohen by power-of-attorney 09/28/2012
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(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) Includes a grant of restricted stock units of which 5,100 remain outstanding awarded to the Reporting Person on September 10, 2010 under the Seagate Technology plc 2004 Stock Compensation Plan. Each restricted stock unit represents a contingent right to receive one share of Seagate ordinary shares. Subject to the Reporting Person's continuous employment, restricted stock units continue to vest and be delivered in equal installments on each of the first four anniversaries of September 10, 2010.
(2) Includes a grant of restricted stock units of which 11,400 remain outstanding awarded to the Reporting Person on September 12, 2011 under the Seagate Technology plc 2004 Stock Compensation Plan. Each restricted stock unit represents a contingent right to receive one share of Seagate ordinary shares. Subject to the Reporting Person's continuous employment, restricted stock units will vest and be delivered in equal installments on each of the first four anniversaries of September 12, 2011.
(3) Includes a grant of restricted stock units of 11,536 awarded to the Reporting Person on September 10, 2012 under the Seagate Technology plc Incentive Equity Award Plan. Each restricted stock unit represents a contingent right to receive one share of Seagate ordinary shares. Subject to the Reporting Person's continuous employment, restricted stock units will vest and be delivered in equal installments on each of the first four anniversaries of September 10, 2012.
(4) Options granted to the Reporting Person under the Issuer's 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 option shares vest in equal monthly installments over the 36 months following September 11, 2010.
(5) Options granted to the Reporting Person under the Issuer's 2001 Share 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 vest in equal monthly installments over the 36 months following September 13, 2011.
(6) 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.
(7) Options granted to the Reporting Person under the Issuer's 2012 Incentive Equity Award Plan are subject to a four-year vesting schedule. One quarter of the option shares vested on September 10, 2013. The remaining option shares vested in equal monthly installments over the 36 months following September 10, 2013.
 
Remarks:
EXHIBIT INDEX
Exhibit 24-Power of Attorney

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