Aden Abdulle Osman Daar (Aaden Cabdulle Cusmaan Daar) (9 December 1908 – 8 June 2007), was a Somali politician.
In February 1944, he joined the Somali Youth Club (later called the Somali Youth League). The group was a nationalist party that wanted independence for Somalia. Daar became a member of the party's steering board. In 1946, he was appointed as the secretary of one section of the party. He was chairman of the Somali Youth League from 1954 to 1956, and again from 1958 to 1959. In 1956, he was elected chairman of the Legislative Assembly.
When Somalia gained its independence on July 1, 1960, Daar was elected as the first president of Somalia. He was beaten in the 1967 presidential election against Abdirashid Ali Shermarke. He finished his term as president on June 10, 1967.