Socialist Party of Italian Workers is the name for a political party that has been used by three distinct organizations of the Left in Italy.

Partito Socialista dei Lavoratori Italiani (1893-1895)

First name of the Partito Socialista Italiano (PSI) from 1893 to 1895.

Partito Socialista dei Lavoratori Italiani (1925-1927)

Name of the Partito Socialista Unitario

United Socialist Party (Italy, 1922–1930)

The United Socialist Party was a social-democratic political party in Italy, active from 1922 to 1930....

 (PSU) from 1925 to 1927.
This association is the most well known.

Partito Socialista dei Lavoratori Italiani (1947-1951)

Name of the Partito Socialista Democratico Italiano (PSDI) from 1947 to 1951.