ChatGPT is owned by OpenAI, with governance overseen by the OpenAI Foundation....

https://www.a1bookmarks.win/chatgpt-is-owned-by-openai-the-company-that-developed-and-maintains-the-ai

ChatGPT is owned by OpenAI, with governance overseen by the OpenAI Foundation. While Microsoft is a major investor and partner, it is not the parent company