Exhibit 31.1



CERTIFICATION OF PRINCIPAL EXECUTIVE
OFFICER AND PRINCIPAL FINANCIAL OFFICER PURSUANT TO RULE 13a-14(a)/15d-14(a) PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934,
AS AMENDED



I, Delome Fair, certify that:



| | 1. | I have reviewed this Annual Report on Form 10-K/A (Amendment No. 1) of Synthesis Energy Systems,
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(s) 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;



(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 preparation of financial statements
for external purposes in accordance with generally accepted accounting principles;



(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



(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



| | 5. | The registrant’s other certifying officer(s) 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 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



(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.



Date:
April 27, 2018





| | /s/ Delome Fair                                                                  
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| | Delome Fair                                                                      
| | President, Chief Executive Officer and Director, and 
principal financial officer