Aluf Yishai Beer (Hebrew: ישי בר; born 1956) is a former general in the Israel Defense Forces, head of a reserve call-up, and former president of the Israeli Military Court of Appeals.

He was drafted into the IDF in 1974 and joined the Paratroopers Brigade. Two years later he took part as a platoon leader in Operation Entebbe, freeing Israeli hostages flown to Uganda. He also participated in Operation Litani and as a reserve in the 1982 Lebanon War. He rejoined the regular service in May 2002 when he was appointed to his current post, although as a doctor of law, he continues to work as a Law professor. During his career Beer received a B.A. from Hebrew University and an M.A. from the London School of Economics. In November 2008, Beer announced his retirement from the IDF.