EX-4.3





 Exhibit 4.3 

[FACE] 
 Number 

Warrants 
 THIS WARRANT
SHALL BE VOID IF NOT EXERCISED PRIOR TO 
 THE EXPIRATION OF THE EXERCISE PERIOD PROVIDED FOR 

IN THE WARRANT AGREEMENT DESCRIBED BELOW 

Supernova Partners Acquisition Company III, Ltd. 

Incorporated Under the Laws of the Cayman Islands 

CUSIP [ ● ] 

Warrant Certificate 
 This Warrant
Certificate certifies that [ ● ], or registered assigns, is the registered holder of [ ● ] warrant(s) (the “Warrants” and each, a “Warrant”) to purchase
Class A ordinary shares, $0.0001 par value (“Ordinary Shares”), of Supernova Partners Acquisition Company III, Ltd., a Cayman Islands exempted company (the “Company”). Each Warrant entitles the
holder, upon exercise during the period set forth in the Warrant Agreement referred to below, to receive from the Company that number of fully paid and nonassessable Ordinary Shares as set forth below, at the exercise price (the “Exercise
Price”) as determined pursuant to the Warrant Agreement, payable in lawful money (or through “cashless exercise” as provided for in the Warrant Agreement) of the United States of America upon surrender of this
Warrant Certificate and payment of the Exercise Price at the office or agency of the Warrant Agent referred to below, subject to the conditions set forth herein and in the Warrant Agreement. Defined terms used in this Warrant Certificate but not
defined herein shall have the meanings given to them in the Warrant Agreement. 
 Each whole Warrant is initially exercisable for one fully paid and non-assessable Ordinary Share. Fractional shares shall not be issued upon exercise of any Warrant. If, upon the exercise of Warrants, a holder would be entitled to receive a fractional interest in an Ordinary Share,
the Company shall, upon exercise, round down to the nearest whole number the number of Ordinary Shares to be issued to the Warrant holder. The number of Ordinary Shares issuable upon exercise of the Warrants is subject to adjustment upon the
occurrence of certain events as set forth in the Warrant Agreement. 
 The initial Exercise Price per one Ordinary Share for any Warrant is equal to $11.50
per share. The Exercise Price is subject to adjustment upon the occurrence of certain events as set forth in the Warrant Agreement. 












 Subject to the conditions set forth in the Warrant Agreement, the Warrants may be exercised only during the
Exercise Period and to the extent not exercised by the end of such Exercise Period, such Warrants shall become void. The Warrants may be redeemed, subject to certain conditions, as set forth in the Warrant Agreement. 

Reference is hereby made to the further provisions of this Warrant Certificate set forth on the reverse hereof and such further provisions shall for all
purposes have the same effect as though fully set forth at this place. 
 This Warrant Certificate shall not be valid unless countersigned by the Warrant
Agent, as such term is used in the Warrant Agreement. This Warrant Certificate shall be governed by and construed in accordance with the internal laws of the State of New York. 

 

			
	SUPERNOVA PARTNERS ACQUISITION COMPANY III, LTD.
		
	By:	 	 
		 	Name:                                     
                                         
    
		 	Title:     Authorized Signatory


  

			
	AMERICAN STOCK TRANSFER & TRUST COMPANY, LLC AS WARRANT AGENT
		
	By:	 	 
		 	Name:                                     
                                         
        
		 	Title:                                    
                                         
           














 [Form of Warrant Certificate] 

[Reverse] 
 The Warrants evidenced by this
Warrant Certificate are part of a duly authorized issue of Warrants entitling the holder on exercise to receive [ ● ] Ordinary Shares and are issued or to be issued pursuant to a Warrant Agreement dated as of [ ● ],
2021 (the “Warrant Agreement”), duly executed and delivered by the Company to American Stock Transfer & Trust Company, LLC, as warrant agent (the “Warrant Agent”), which Warrant Agreement is
hereby incorporated by reference in and made a part of this instrument and is hereby referred to for a description of the rights, limitation of rights, obligations, duties and immunities thereunder of the Warrant Agent, the Company and the holders
(the words “holders” or “holder” meaning the Registered Holders or Registered Holder, respectively) of the Warrants. A copy of the Warrant Agreement may be obtained by the holder hereof upon written
request to the Company. Defined terms used in this Warrant Certificate but not defined herein shall have the meanings given to them in the Warrant Agreement. 

Warrants may be exercised at any time during the Exercise Period set forth in the Warrant Agreement. The holder of Warrants evidenced by this Warrant
Certificate may exercise them by surrendering this Warrant Certificate, with the form of Election to Purchase set forth hereon properly completed and executed, together with payment of the Exercise Price as specified in the Warrant Agreement (or
through “cashless exercise” as provided for in the Warrant Agreement) at the principal corporate trust office of the Warrant Agent. In the event that upon any exercise of Warrants evidenced hereby the number of Warrants exercised
shall be less than the total number of Warrants evidenced hereby, there shall be issued to the holder hereof or his, her or its assignee, a new Warrant Certificate evidencing the number of Warrants not exercised. 

Notwithstanding anything else in this Warrant Certificate or the Warrant Agreement, no Warrant may be exercised unless at the time of exercise (i) a
registration statement covering the issuance of the Ordinary Shares to be issued upon exercise is effective under the Securities Act and (ii) a prospectus thereunder relating to the Ordinary Shares is current, except through “cashless
exercise” as provided for in the Warrant Agreement. 
 The Warrant Agreement provides that upon the occurrence of certain events the number of
Ordinary Shares issuable upon exercise of the Warrants set forth on the face hereof may, subject to certain conditions, be adjusted. If, upon exercise of a Warrant, the holder thereof would be entitled to receive a fractional interest in an Ordinary
Share, the Company shall, upon exercise, round down to the nearest whole number of Ordinary Shares to be issued to the holder of the Warrant. 
 Warrant
Certificates, when surrendered at the principal corporate trust office of the Warrant Agent by the Registered Holder thereof in person or by legal representative or attorney duly authorized in writing, may be exchanged, in the manner and subject to
the limitations provided in the Warrant Agreement, but without payment of any service charge, for another Warrant Certificate or Warrant Certificates of like tenor evidencing in the aggregate a like number of Warrants. 












 Upon due presentation for registration of transfer of this Warrant Certificate at the office of the Warrant
Agent a new Warrant Certificate or Warrant Certificates of like tenor and evidencing in the aggregate a like number of Warrants shall be issued to the transferee(s) in exchange for this Warrant Certificate, subject to the limitations provided in the
Warrant Agreement, without charge except for any tax or other governmental charge imposed in connection therewith. 
 The Company and the Warrant Agent may
deem and treat the Registered Holder(s) hereof as the absolute owner(s) of this Warrant Certificate (notwithstanding any notation of ownership or other writing hereon made by anyone), for the purpose of any exercise hereof, of any distribution to
the holder(s) hereof, and for all other purposes, and neither the Company nor the Warrant Agent shall be affected by any notice to the contrary. Neither the Warrants nor this Warrant Certificate entitles any holder hereof to any rights of a
shareholder of the Company. 












 Election to Purchase 

(To Be Executed Upon Exercise of Warrant) 
 The
undersigned hereby irrevocably elects to exercise the right, represented by this Warrant Certificate, to receive [        ] Ordinary Shares and herewith tenders payment for such Ordinary Shares to the order of
Supernova Partners Acquisition Company III, Ltd. (the “Company”) in the amount of $[        ] in accordance with the terms hereof. The undersigned requests that a certificate for such
Ordinary Shares be registered in the name of [        ], whose address is [        ] and that such Ordinary Shares be delivered to
[        ] whose address is [        ]. If said [        ] number of Ordinary Shares is less than all of the Ordinary Shares
purchasable hereunder, the undersigned requests that a new Warrant Certificate representing the remaining balance of such Ordinary Shares be registered in the name of [        ], whose address is
[        ] and that such Warrant Certificate be delivered to [        ], whose address is [        ]. 

In the event that the Warrant has been called for redemption by the Company pursuant to Section 6.2 of the Warrant Agreement and a
holder thereof elects to exercise its Warrant pursuant to a Make-Whole Exercise, the number of Ordinary Shares that this Warrant is exercisable for shall be determined in accordance with subsection 3.3.1(c) or
Section 6.2 of the Warrant Agreement, as applicable. 
 In the event that the Warrant is a Private Placement Warrant that is to be
exercised on a “cashless” basis pursuant to subsection 3.3.1(c) of the Warrant Agreement, the number of Ordinary Shares that this Warrant is exercisable for shall be determined in accordance with subsection 3.3.1(c) of the
Warrant Agreement. 
 In the event that the Warrant is to be exercised on a “cashless” basis pursuant to Section 7.4 of
the Warrant Agreement, the number of Ordinary Shares that this Warrant is exercisable for shall be determined in accordance with Section 7.4 of the Warrant Agreement. 

In the event that the Warrant may be exercised, to the extent allowed by the Warrant Agreement, through cashless exercise (i) the number of Ordinary
Shares that this Warrant is exercisable for would be determined in accordance with the relevant section of the Warrant Agreement which allows for such cashless exercise and (ii) the holder hereof shall complete the following: The undersigned
hereby irrevocably elects to exercise the right, represented by this Warrant Certificate, through the cashless exercise provisions of the Warrant Agreement, to receive Ordinary Shares. If said number of shares is less than all of the Ordinary Shares
purchasable hereunder (after giving effect to the cashless exercise), the undersigned requests that a new Warrant Certificate representing the remaining balance of such Ordinary Shares be registered in the name of
[        ], whose address is [        ] and that such Warrant Certificate be delivered to [        ], whose address is
[        ]. 
 [Signature Page Follows] 












 Date: [            ],
20[    ] 
  

			
	(Signature)
	
	(Address)
	
	(Tax Identification Number)


 Signature Guaranteed: 

________________________________________ 
 THE SIGNATURE(S)
SHOULD 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 S.E.C. RULE 17Ad-15 UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED).