Birger Sjöberg (1885–1929) was a Swedish poet, novelist and songwriter, whose best-known works include the faux-naïf song collection Fridas Bok (Frida's Book) and the novel Kvartetten Som Sprängdes (The Quartet That Split Up), a somewhat Dickensian relation about stock-exchange gambling in the twenties, and the frantic efforts to recover.

Originally a journalist, Sjöberg wrote songs in his spare time. His debuted as a serious writer with the 1922 publication of Fridas Bok (Frida's Book), which was both a critical and popular success. Following a series of concert tours, he withdrew from public life and focused on his writing.

After his death in 1929, a new series of songs and a selection of poems were published.