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 material fact or
omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements
were 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 included in this
report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant
as 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 and maintaining
disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over 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 disclosure
controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including
its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this
report is being prepared;
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| | (b) | Designed such internal control over financial reporting, or caused such internal
control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability
of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted
accounting principles;
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| | (c) | Evaluated the effectiveness of the registrant's disclosure controls and procedures
and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of
the 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 control
over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth
fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the
registrant’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 most recent evaluation
of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of
directors (or persons performing the equivalent functions):
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| | (a) | All significant deficiencies and material weaknesses in the design or operation
of 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 employees
who have a significant role in the registrant's internal control over financial reporting.
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Date: July 31, 2018



| | /S/ John Simard                                                                                
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| | John Simard
        Chief Executive Officer and President
        (Principal Executive Officer)