ChatGPT is owned by OpenAI, the organization that developed the AI platform....

https://josuesbestword.quillnesty.com/posts/what-should-a-comms-team-say-instead-of-microsoft-owns-chatgpt

ChatGPT is owned by OpenAI, the organization that developed the AI platform. The OpenAI Foundation oversees governance to guide its mission and ensure responsible use. Microsoft is a significant investor and partner but does not own or control ChatGPT