Which us president was sworn in by his father?

Calvin Coolidge

was sworn in by his father, a notary public, when he assumed the presidency in 1923 after Warren Harding's death.

Calvin Coolidge's oath in 1925 was administered by Chief Justice (and ex-president) William Taft. It was also the first inaugural address broadcast on the radio. Coolidge was sworn in by his father, a notary public, when he assumed the presidency in 1923 after Warren Harding's death.