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

https://www.pop-bookmarks.win/discover-who-really-owns-chatgpt-in-this-clear-up-to-date-explainer-openai

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