The Socialist Party of Wisconsin (SPWI) is the state chapter of the Socialist Party USA (SPUSA)[citation needed] in the U.S. state of Wisconsin.

The Socialist Party had two locals, the Milwaukee County Local and the South Central Wisconsin Local.

[citation needed] The Socialist Party of America voted 73:34 to change its name to Social Democrats, USA in December 1972.

[citation needed] The Socialist Party of Wisconsin sees itself as a continuation of the Social-Democratic Party of Wisconsin, state affiliate of the Socialist Party of America.

[citation needed] This organization elected a number of candidates to office over the three-quarters of a century of its existence.