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 *
McDermott Adrian
  2. Issuer Name and Ticker or Trading Symbol
Zendesk, Inc. [ZEN]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
SVP of Product Development
(Last)
(First)
(Middle)
1019 MARKET STREET
3. Date of Earliest Transaction (Month/Day/Year)
12/15/2015
(Street)

SAN FRANCISCO, CA 94103
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
Common Stock 12/15/2015   M   2,604 A (1) 87,231 D  
Common Stock 12/15/2015   F   979 (2) D $ 26.13 86,252 D  
Common Stock 12/16/2015   M(3)   21,440 A $ 0.11 107,692 D  
Common Stock 12/16/2015   S(3)   21,440 D $ 25.9701 (4) 86,252 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
Restricted Stock Unit (1) 12/15/2015   M     2,604   (5) 02/04/2022 Common Stock 2,604 (1) 98,959 D  
Stock Option (Right to Buy) $ 0.11 12/16/2015   M(3)     21,440   (6) 09/09/2020 Common Stock 21,440 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
McDermott Adrian
1019 MARKET STREET
SAN FRANCISCO, CA 94103
      SVP of Product Development  

Signatures

 /s/ John Geschke, Attorney-in-Fact for Adrian McDermott   12/16/2015
**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) Restricted stock units convert into common stock on a one-for-one basis.
(2) Represents the number of shares withheld by the Issuer in satisfaction of tax withholding obligations in connection with the vesting of the restricted stock units listed in Table II. Such withholding is mandated by an election of the Issuer made in advance and does not represent a discretionary trade by the reporting person.
(3) This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person.
(4) This sale price represents the weighted average sale price of the shares sold ranging from $25.71 to $26.14 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
(5) 1/48th of the shares issuable pursuant to the restricted stock units shall vest monthly after the vesting commencement date of February 15, 2015, subject to the Reporting Person's continuous service to the Issuer on each such date. Unvested shares are subject to acceleration upon the occurrence of certain events.
(6) 1/4th of the shares subject to the option vested on July 26, 2011 and 1/48th of the shares vested monthly thereafter through July 26, 2014.

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