|Date of birth||10 March 1923|
|Place of birth||Jerusalem, Mandatory Palestine|
|Date of death||29 June 1987(aged 64)|
|Knessets||6, 7, 8, 9|
|Faction represented in Knesset|
|1977–1978||Democratic Movement for Change|
|1977–1980||Minister of Justice|
Shmuel M. Tamir (Hebrew: שמואל תמיר, born Shmuel Katzenelson on 10 March 1923, died 29 June 1987) was a prominent Israeli independence fighter, lawyer, Knesset member from 1965 to 1980, and Minister of Justice in the government of Menachem Begin from 1977 until 1980
Born in Jerusalem, Katzenelson joined the Irgun in 1938 and after the declaration of the Revolt in February 1944, and took part in operations against British targets, most notably the 26 February 1944 attack on income tax offices in Jerusalem. During 1946 he served as Deputy Commander of the Jerusalem District and was in charge of the Irgun Intelligence unit in Jerusalem.
He was arrested by the British several times, and in March 1947 was exiled to Detention Camps in Africa where he finished his Law studies. In the camp he served as the Supervisor who represented the detainees to the British Authorities.
Katzenelson returned home with the last exiles from Kenya on July 12, 1948, after Israeli independence was declared; upon arriving in Israel, he adopted his code name, Tamir (meaning "tall and slender") as his legal name. He had a notable career as a lawyer and conducted several famous political cases, including the Yedidya Segal and Rudolf Kastner trials.
In 1966 he was expelled from the party, and together with two others, formed the Free Centre. He was re-elected in 1969, and again in 1973, by which time the party had merged into Likud. He resigned from the Knesset in January 1977, and soon after joined the new centrist party, the Democratic Movement for Change (Dash). He was returned to the Knesset in the 1977 elections on Dash's list, and was appointed Minister of Justice in the Begin government. As Dash disintegrated, Tamir joined the Democratic Movement, before leaving to sit as an independent MK. He resigned from the cabinet in August 1980, and lost his seat in the 1981 election.
Shmuel was the son of Reuven Katzenelson (a member of the Jewish Legion and Joseph Trumpeldor's sergeant and companion in the Battle of Gallipoli) and Batsheva Katznelson (a member of the Knesset). Two of his uncles were Joseph Katzenelson, a companion of Ze'ev Jabotinsky and one of the Irgun's two Chiefs of Illegal Immigration and Avraham Katznelson, one of the signatories of the Israeli declaration of independence, and his aunt was Rachel Katznelson-Shazar, wife of Zalman Shazar, the third President of Israel.