Yosef Avni (born December 25, 1924) is a former Irgun activist. He was born Yosef Danochin in Jerusalem, British Mandate of Palestine, changing his name to Avni (his underground identity) after the establishment of the State of Israel in 1948.
Avni went to work as a locksmith at a young age, to help provide for his family (learned his job at his cousins' workshop, the Sabah brothers). At the age of 16 he joined Betar, leaving four years later (in 1942) for the Irgun. After the declaration of the Revolt against the British authorities (February 1944), Avni became part of the fighting force, and on top of being in charge of an arms dump in Jerusalem took part in many operations.
In the second attack on the British intelligence offices in the Russian Compound (December 27, 1945) Avni was in charge of the sappers unit. He also took part in the King David Hotel bombing and the attack on Camp Schneller.
Avni was arrested in 1947 and detained by the British in Latrun Camp. He was released in March 1948, and was wounded attacking the Muchtar's house during the events of the Deir Yassin massacre.