Sphere Entertainment Co.

As previously disclosed, on June 26, 2024, our Board authorized a change in our fiscal year-end from June 30 to December 31, effective December 31, 2024, resulting in a six-month transition period from July 1, 2024 to December 31, 2024. As a result, our annual meeting of stockholders is being accelerated to coincide with the cadence of the new fiscal year-end and will be held on Wednesday, June 4, 2025, at 10:00 a.m. Eastern Time (the “annual meeting”).

These proxy materials are provided in connection with the solicitation of proxies by our Board for the annual meeting, which will be conducted via live webcast on Wednesday, June 4, 2025 at 10:00 a.m. Eastern Time. You can attend the annual meeting via the internet by visitingwww.virtualshareholdermeeting.com/SPHR2025.

This proxy statement is first being sent to stockholders on or about April 22, 2025. Unless otherwise indicated, references to the “2024 Transition Period” and the “transition period ended December 31, 2024” refer to the Company’s six-month transition period from July 1, 2024 to December 31, 2024, and references to “2024”, “2023” and “2022” or “2024 fiscal year”, “2023 fiscal year” and “2022 fiscal year” refer to the Company’s fiscal years ended on June 30 of such years.