Francisco Eusébio Lourenço Leão (2 February 1864 – 21 November 1926) was a Portuguese physician and republican politician.

He practised medicine in his hometown of Gavião, and then specialised in urology in Paris and Berlin.

He was politically active in Lisbon, especially after the 1890 British Ultimatum, contributing to several publications as a vocal proponent of the republican ideals.

[1] Eusébio Leão was one of the founders of the newspaper A Pátria and, in October 1909, was elected Secretary to the Directory of the Portuguese Republican Party.

After the Republican Revolution in 1910, during which he was one of the people who proclaimed the new regime from the balcony of the Lisbon City Hall, he was made Civil Governor of the Lisbon District, and was elected member of the National Constituent Assembly to draft a new constitution.