Otto Julius Hufnagel (4 October 1885 – 11 November 1944) was a German teacher and politician (DDP).
Born in Frankfurt am Main, Hufnagel was the son of the teacher Johannes Hufnagel and his wife Ida Marie Henriette née Aschenbrenner.
In 1912 he became a senior teacher in Bad Arolsen and was promoted to a student councilor there in 1924.
From 1919 to 1922 he was a member of parliament for the DDP in the Waldecker Landesvertretun [de].
Hufnagel died in Westerburg at the age of 59.