Mordechai Alkahi (Hebrew: מרדכי אלקחי; 10 March 1925 – 16 April 1947) was a member of the Irgun Jewish guerrilla organization in pre-state Mandatory Palestine, and one of 12 Olei Hagardom executed by the British during the Jewish insurgency in Palestine.
Alkahi was born in Petah Tikva to an impoverished family. His parents were Jewish immigrants from Turkey. At age 14, he left school and began working to support his family. In his youth, he joined the Maccabi youth movement, a youth movement promoting physical activity and sports, and he became a prominent athlete, particularly in swimming. In 1941, he won first place in a national competition.
In late 1943, Alkahi joined the Irgun, which shortly afterward began an insurrection against British rule. After undergoing military training, he joined the Irgun's Combat Corps, or Hayil Kravi (HaK). Even after joining the Irgun, he continued to work in a factory by day, and took part in raids at night. His first Irgun operation was an attack on the Tegart fort in Qalqilya, one of the four Tegart forts attacked that night. The raid failed when the British police saw the attackers approach and poured a withering fire on them, wounding four and forcing them to retreat. Alkahi helped rescue the wounded during this attack.
Alkahi went on to participate in sabotage operations against the telephone network and railways, and arms raids on British camps in Netanya, Tel Aviv, and Rosh HaAyin. On April 23, 1946, he participated in an arms raid on the Ramat Gan police station, in which a large quantity of weapons and munitions were stolen. In the course of that operation, two Irgun fighters were killed and one, Dov Gruner, who would later hang alongside Alkahi, was captured.