The New Union Party (NUP) was a small political party in the United States. It was originally formed in 1974 as the New Unionists, several of whom had been members of Section Minneapolis of Socialist Labor Party of America (SLP). As with many such departures since the 1920s, they claimed SLP had become bureaucratic and authoritarian in its internal party structure. In December 1980, New Unionists fused with the League for Socialist Reconstruction (LSR) and two smaller groups and proclaimed the "New Union Party." In that year, New Unionist editor Jeff Miller ran for US Congress in Minnesota's Fifth District, polling 1.4% of the total vote.
Traditionally the NUP has been a DeLeonist militant democratic socialist party which "advocates political and social revolution" but denounces violence and is "committed to lawful activities to overthrow the capitalist economic system." In 2013, New Union Party abandoned publication of their official newsletter, New Unionist. In the same year, it began a Campaign for a Working Democracy and Jeff Miller's run for US Senate in Minnesota. The new campaign materials lacked any reference to Marxism or DeLeonism, or socialism. The website is now inactive.