International Socialist League (UK)

''This is about the UK organisation. For the Latin American organization named International Socialist League, see International Socialist League (Latin America). For the former syndicalist group named International Socialist League, see International Socialist League (South Africa)''

The International Socialist League is a small Trotskyist organisation in Britain. Its irregular publication, Socialist Voice, was published frequently until 2002.

The group's origins lie in the disintegration of the Workers' Revolutionary Party (WRP) in the 1980s. It was founded as the Bolshevik Faction of Cliff Slaughter's WRP in August 1987 and from the start was sympathetic to the Latin American-based Trotskyist leader Nahuel Moreno.

In February 1988 the future ISL split from the WRP and under the leadership of the veteran Bill Hunter and Martin Ralph founded their organisation, which affiliated to Moreno's International Workers League (LIT).

The ISL remains active in the North West of England where its small membership is concentrated and it was active in the Socialist Alliance. It is supportive of the Socialist Alliance Democracy Platform and the Merseyside-based United Socialist Party.

Between 2000 and 2006 the League published a website, socialistvoice.org. It went offline sometime after June 14, 2006.