Riksdag (rēks´däg, rēks´tä), national parliament of Sweden, formed in 1866. Originally a two-chamber legislature, it became a single chamber body in 1971. Representation in the chamber is proportional. Members are elected by universal suffrage for a term of three years. The cabinet is responsible to the Riksdag. A new constitution, effective in Jan., 1975, which eliminated the monarch's residual authority, gave the speaker of the Riksdag rather than the king the right to appoint a new premier.