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 *
  Mosbrooker Eric
 2. Date of Event Requiring Statement (Month/Day/Year)
08/23/2017		 3. Issuer Name and Ticker or Trading Symbol
Horizon Pharma plc [HZNP]
(Last)
(First)
(Middle)
C/O HORIZON PHARMA PLC, CONNAUGHT HOUSE, 1ST FL, 1 BURLINGTON RD		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
SVP, Orphan Business Unit
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

DUBLIN, L2 4		 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 1,465
D
 

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
Stock Option (Right to Buy)   (1) 10/31/2026 Ordinary Shares 28,233 $ 16.91 D  
Restricted Stock Units (RSU)   (2)   (2) Ordinary Shares 17,741 $ (2) D  
Restricted Stock Units (RSU)   (3)   (3) Ordinary Shares 7,500 $ (3) D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Mosbrooker Eric
C/O HORIZON PHARMA PLC
CONNAUGHT HOUSE, 1ST FL, 1 BURLINGTON RD
DUBLIN, L2 4		       SVP, Orphan Business Unit  

Signatures

/s/ Paul W. Hoelscher, Attorney-in-Fact 08/28/2017
**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) 25% of the shares subject to the option vest and become exercisable on the first anniversary of the date of grant (November 1, 2016), and the remaining shares vest in 36 equal monthly installments thereafter.
(2) Each restricted stock unit represents a contingent right to receive one ordinary share of the Issuer. The restricted stock units vest 25% annually on each anniversary of the date of grant (November 1, 2016).
(3) Each restricted stock unit represents a contingent right to receive one ordinary share of the Issuer. The restricted stock units vest 50% on June 1, 2018 and 50% on June 1, 2019.

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