Carlo Rosselli (16 November 18999 June 1937) was an Italian political leader, journalist, historian and anti-fascist activist, first in Italy then abroad. He developed a theory of reformist, non-Marxist Socialism inspired by the British Labour movement, that he described as "liberal Socialism". Rosselli founded the anti-fascist militant movement Giustizia e Libertà. Rosselli personally took part in combat in the Spanish Civil War where he served on the Republican side.