SP-A may refer to:

• Socialistische Partij Anders, the Socialist Party of Flanders, Belgium
• Surfactant protein A

Socialist Party Differently (, sp.a) is a social-democratic Flemish political party in Belgium. The party, formerly known as the Belgische Socialistische Partij (BSP) 1978–80 and the Socialistische Partij (SP) 1980–2001, had branched off from the Belgian Socialist Party in 1978; the Belgian Socialist Party was itself formed by former members of the Belgian Labour Party. From December 2011 to September 2014, sp.a was part of the Di Rupo Government, along with its Francophone counterpart Socialist Party (PS). Sp.a has been several times part of the Flemish Government.