**Exhibit 31.1**

 

**CERTIFICATIONS**

 

I, John Simard, certify that:

 

| 1. |  | I have reviewed this Annual Report on Form 10-K of XBiotech Inc.; |
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| 2. |  | Based on my knowledge, this report does not contain any untrue statement of a materialfact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statementswere made, not misleading with respect to the period covered by this report; |
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| 3. |  | Based on my knowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrantas of, and for, the periods presented in this report; |
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| 4. |  | The registrant's other certifying officer and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal controlover financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have: |
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|  | (a) | Designed such disclosure controls and procedures, or caused such disclosurecontrols and procedures to be designed under our supervision, to ensure that material information relating to the registrant, includingits consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which thisreport is being prepared; |
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|  | (b) | Designed such internal control over financial reporting, or caused such internalcontrol over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliabilityof financial reporting and the preparation of financial statements for external purposes in accordance with generally acceptedaccounting principles; |
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|  | (c) | Evaluated the effectiveness of the registrant's disclosure controls and proceduresand presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end ofthe period covered by this report based on such evaluation; and |
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|  | (d) | Disclosed in this report any change in the registrant’s internal controlover financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourthfiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, theregistrant’s internal control over financial reporting; and |
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| 5. |  | The registrant's other certifying officer and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant'sboard of directors (or persons performing the equivalent functions): |
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|  | (a) | All significant deficiencies and material weaknesses in the design or operationof internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record,process, summarize and report financial information; and |
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|  | (b) | Any fraud, whether or not material, that involves management or other employeeswho have a significant role in the registrant's internal control over financial reporting. |
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Date: September 4, 2018

 

/S/ John Simard

John SimardChief Executive Officer and President (Principal ExecutiveOfficer)