Bolshevik-Leninist Party of India, Ceylon and Burma (BLPI) was formed in 1942 as a unification of two Indian groups and Lanka Sama Samaja Party of Ceylon. BLPI became recognized as a section of the Fourth International.

BLPI remained a very small party during world War II, far from the expectations of a massive united revolutionary party for the entire Subcontinent. Most probably no branch ever existed in Burma, the inclusion of Burma in the party name was more of an expression of an intention to expand there. In Ceylon, LSSP had some activities before the war, but the suppression of the party by the colonial authorities and the exile of various leaders to India weakened it severely. Also, the decision to merge LSSP with BLPI was not well established with the primary leaders of the party, who were in British jails. In India, BLPI had activities in a few areas. The majority of the activists were exiled LSSPers who were concentrated in Bombay.

BLPI supported the Quit India Movement.

After the war, when the Lankans returned home, BLPI collapsed. The Lankan members reorganized their party under the name Bolshevik Samasamaja Party . The remains of BLPI were concentrated in Calcutta, where the party was active in trade union work. In 1948, the Fourth International asked the party to enter the Socialist Party of India and practice entryism there.