The Socialist Party of Colorado was an affiliate of the Socialist Party of America, lasting from the first decade of the twentieth century to at least the 1950s.^{[citation needed]} Later there was a Socialist Party of Colorado affiliated with the Socialist Party USA.^{[citation needed]} The Socialist Party of Colorado engages in both electoral politics and non-electoral activism.^{[citation needed]}

Since 1976, the Socialist Party USA has run a candidate for President of the United States.^{[citation needed]} The party's nominee has been on the ballot in Colorado in each election since 1996.^{[citation needed]} The candidate who has received the highest vote total in Colorado was peace activist David McReynolds in 2000.^{[citation needed]}