Adolf Johan (Aatto) Sirén (23 December 1873 – 14 March 1955) was a Finnish smallholder and politician, born in Orimattila.

During the Finnish Civil War of 1918, Sirén was a member of the Central Workers' Council of Finland, the legislature of the Finnish Socialist Workers' Republic.

After the defeat of the Red side, he went into exile in Soviet Russia.

In September 1921, he was given a prison sentence of nine years for his role in the Civil War.

This article about a Social Democratic Party of Finland politician is a stub.