Exhibit 4.1


 


[Form of Unit Certificate]


NUMBER
UNITS

U-


 


SEE REVERSE FOR
CERTAIN DEFINITIONS


CUSIP [              ]


 


SPARTAN ACQUISITION CORP. II


 


UNITS CONSISTING OF ONE SHARE OF CLASS
A COMMON STOCK AND

ONE-HALF OF ONE REDEEMABLE WARRANT TO PURCHASE ONE SHARE OF CLASS A COMMON STOCK


 


THIS CERTIFIES THAT                                          is the owner
of                                          Units.


 


Each Unit (“Unit”)
consists of one (1) share of Class A common stock, par value $0.0001 per share (“Common Stock”), of Spartan
Acquisition Corp. II, a Delaware corporation (the “Company”), and one-half of one redeemable warrant
(each whole warrant, a “Warrant”). Each Warrant entitles the holder to purchase one (1) share (subject
to adjustment) of Common Stock for $11.50 per share (subject to adjustment). Only whole Warrants are exercisable. Each Warrant
will become exercisable on the later of (i) thirty (30) days after the Company’s completion of a merger, capital stock exchange,
asset acquisition, stock purchase, reorganization or other similar business combination with one or more businesses (each a “Business
Combination”), or (ii) twelve (12) months from the closing of the Company’s initial public offering, and will
expire unless exercised before 5:00 p.m., New York City Time, on the date that is five (5) years after the date on which the Company
completes its initial Business Combination, or earlier upon redemption or liquidation (the “Expiration Date”).
The Common Stock and Warrants comprising the Units represented by this certificate are not transferable separately prior to [              
], 2020, unless Citigroup Global Markets Inc., Credit Suisse Securities (USA) LLC and Cowen and Company, LLC elect to allow earlier
separate trading, subject to the Company’s filing of a Current Report on Form 8-K with the Securities and Exchange Commission
containing an audited balance sheet reflecting the Company’s receipt of the gross proceeds of the offering and issuing a
press release announcing when separate trading will begin. No fractional Warrants will be issued upon separation of the Units.
The terms of the Warrants are governed by a Warrant Agreement, dated as of [                ],
2020, between the Company and Continental Stock Transfer & Trust Company, as Warrant Agent, and are subject to the terms and
provisions contained therein, all of which terms and provisions the holder of this certificate consents to by acceptance hereof.
Copies of the Warrant Agreement are on file at the office of the Warrant Agent at 1 State Street, 30th Floor, New York, New York
10004, and are available to any Warrant holder on written request and without cost.


 


Upon consummation of
a Business Combination, the United represented by this certificate will automatically separate into the shares of Common Stock
and Warrants comprising such Units.


 


This certificate is not
valid unless countersigned by the Transfer Agent and Registrar of the Company.


 


This certificate shall
be governed by and construed in accordance with the internal laws of the State of New York.


 


Witness the facsimile
signature of its duly authorized officers. 


 


		 	
	Secretary	 	Chief Executive Officer


 






    


    	 



    

 


Spartan Acquisition Corp. II


 


The Company will furnish
without charge to each unitholder who so requests, a statement of the powers, designations, preferences and relative, participating,
optional or other special rights of each class of stock or series thereof of the Company and the qualifications, limitations, or
restrictions of such preferences and/or rights.


 


The following abbreviations,
when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according
to applicable laws or regulations:


 


	TEN COM	–	as tenants in common	 	UNIF GIFT MIN ACT	–		Custodian	 
	TEN ENT	–	as tenants by the entireties	 	 	 	(Cust)	 	(Minor)


 


	JT TEN	–	as joint tenants with right of survivorship and not as tenants in common	 	 	 	
        under
        Uniform Gifts to Minors Act

        (State)



  


Additional abbreviations may also be used
though not in the above list.


 


For value received,                          
hereby sell, assign and transfer unto                                             


 


 





 



PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING
NUMBER OF ASSIGNEE


 





 





 



(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS,
INCLUDING ZIP CODE, OF ASSIGNEE)


 


 





 






 





 



 





 



 


Units represented by the within Certificate,
and do hereby irrevocably constitute and appoint Attorney to transfer the said Units on the books of the within named Company with
full power of substitution in the premises. 


 


	Dated: 	 	 



 





		Notice:  	The signature to this assignment must correspond with the name as written upon the face of the certificate
in every particular, without alteration or enlargement or any change whatever.



 


	Signature(s) Guaranteed:	 



THE SIGNATURE(S)
MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS
WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM, PURSUANT TO RULE 17Ad-15 UNDER THE SECURITIES EXCHANGE ACT
OF 1934, AS AMENDED (OR ANY SUCCESSOR RULE)).  




 






    


    	 



    

 








In each case, as more
fully described in the Company’s final prospectus dated [           ],
2020, the holder(s) of this certificate shall be entitled to receive a pro-rata portion of certain funds held in the trust account
established in connection with the Company’s initial public offering only in the event that (i) the Company redeems the shares
of Common Stock sold in its initial public offering and liquidates because it does not consummate an initial Business Combination
within the period of time set forth in the Company’s amended and restated certificate of incorporation, as may be amended
from time to time (the “Charter”), (ii) the Company redeems the shares of Common Stock sold in its initial
public offering in connection with a stockholder vote to approve an amendment to the Charter that would affect the substance or
timing of the Company’s obligation to redeem 100% of the Common Stock if it does not consummate an initial Business Combination
within the period of time set forth therein, or (iii) if the holder(s) seek(s) to redeem for cash his, her or its respective shares
of Common Stock in connection with a tender offer (or proxy solicitation, solely in the event the Company seeks stockholder approval
of the proposed initial Business Combination) setting forth the details of a proposed initial Business Combination. In no other
circumstances shall the holder(s) have any right or interest of any kind in or to the trust account.