not that I know of

not that I know of

1. Used to indicate that the response is probably no, but that the speaker is not entirely certain.

• “not that I know of” in Longman Dictionary of Contemporary English, Longman.
• “not that I know of”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.
• “not that I know of”, in Collins English Dictionary.