Exhibit 99.1

STANDARD FORM TR-1

VOTING RIGHTS ATTACHED TO SHARES – ARTICLE 12(1) OF DIRECTIVE 2004/109/EC

FINANCIAL INSTRUMENTS – ARTICLE 11(3) OF THE COMMISSION DIRECTIVE 2007/14/ECi

1. Identity of the issuer or the underlying issuer of existing shares to which voting rights are attached ii:

FLUTTER ENTERTAINMENT PLC

2. Reason for the notification (please tick the appropriate box or boxes):

 

  ☒

an acquisition or disposal of voting rights

 

  ☐

an acquisition or disposal of financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

 

  ☐

an event changing the breakdown of voting rights

3. Full name of person(s) subject to the notification obligationiii:

BlackRock, Inc.

4. Full name of shareholder(s) (if different from 3.)iv:

See Section 9

5. Date of the transaction and date on which the threshold is crossed or reachedv: 27/06/2025

6. Date on which issuer notified: 30/06/2025

7. Threshold(s) that is/are crossed or reached:

Holdings for BlackRock, Inc. have gone above 5%.

8. Notified details:

 

A) Voting rights attached to shares

 

Class/type of shares (if possible using the ISIN CODE)

    Situation previous to the
Triggering transaction vi		      Resulting situation after the triggering transactionviiviii  
     Number of
Sharesix		      Number of
Voting
rightsx		      Number of
sharesxi		      Number of voting rightsxii      % of voting rights  
     Direct      Directxiii      Indirectxiv      Direct     Indirect  

IE00BWT6H894

      N/A        6,980,705        N/A        N/A        9,464,392        N/A       5.35 % 

SUBTOTAL A (based on
aggregate voting rights)

               9,464,392           5.35 %   

B) Financial Instruments

 

Resulting situation after the triggering transactionxv

 

Type of financial instrument

    Expiration Datexvi   

Exercise/Conversion Period/ Datexvii

    Number of voting
rights that may be
acquired if the
instrument is
exercised/
converted		      % of voting rights  
  

SUBTOTAL B (in relation to all expiration dates)

      

 

Total (A+B)

    number of voting rights      % of voting rights  

9,464,392

      9,464,392        5.35 % 

9. Chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held, if applicablexviii:

Each of the following entities, which are wholly owned subsidiaries of BlackRock, Inc., hold the following interests in voting rights in their capacity as Investment Manager on behalf of clients:

 

Investment Manager

    Voting Rights      %  

BlackRock Institutional Trust Company, National Association

      3,800,681        2.15 % 

BlackRock Fund Advisors

      3,158,107        1.78 % 

BlackRock Advisors (UK) Limited

      834,571        0.47 % 

BlackRock Advisors, LLC

      489,931        0.27 % 

BlackRock Japan Co., Ltd.

      343,060        0.19 % 

BlackRock Investment Management (UK) Limited

      334,087        0.18 % 

BlackRock Investment Management, LLC

      146,883        0.08 % 

BlackRock Asset Management Canada Limited

      135,686        0.07 % 

BlackRock (Singapore) Limited

      108,374        0.06 % 

BlackRock Investment Management (Australia) Limited

      64,208        0.03 % 

Aperio Group, LLC

      27,753        0.01 % 

BlackRock Financial Management, Inc.

      16,698        0.00 % 

BlackRock Asset Management North Asia Limited

      4,353        0.00 % 

10. In case of proxy voting: [name of the proxy holder] will cease to hold [number] voting rights as of [date].

11. Additional information:

Done at 12 Throgmorton Avenue, London, EC2N 2DL, U.K. on 30 June 2025