Steponas Kairys was a Lithuanian engineer, nationalist, and social democrat. He was among the 20 men to sign the Act of Independence of Lithuania on 16 February 1918.

The signatories of the Act of Independence of Lithuania were the twenty Lithuanian men who signed the Act of Independence of Lithuania on February 16, 1918. The signatories were elected to the Council of Lithuania by the Vilnius Conference in September 1917 and entrusted with the mission of establishing an independent Lithuanian state. The proclaimed independence was established only in late 1918, after Germany lost World War I and its troops retreated from Lithuanian territory. What followed was a long process of building the state, determining its borders, and gaining international diplomatic recognition. The signatories succeeded in their mission and independent Lithuania survived until the Soviet Union occupied the state on June 15, 1940.