Léon Nicole (10 April 1887 in Montcherand, Vaud – 28 June 1965 in Geneva) was a prominent trade unionist, journalist, politician and member of the Grand Council of Geneva and the Swiss National Council.

Nicole attended school in his home village and Orbe before leaving for further education in St. Gallen.

Nicole joined the Swiss Socialist Party in 1909 and was active as a trade unionist.

He was one of the leaders of the 1918 general strike in Geneva, was imprisoned and subsequently acquitted by a military court in 1919.

In 1933, he was the first Socialist to be elected leader of a canton of Switzerland, when on 3 December he was voted into the Présidence (Presidency) of the Geneva Council of State, the executive body of the Republic and Canton of Geneva.