The Sikkim State Congress, or SSC, was an annexationist political party in the Kingdom of Sikkim. It was founded in 1947 and worked closely with the Indian National Congress (INC) to successfully achieve the annexation of Sikkim to India. Other parties established by the INC to serve India's interests in its near abroad included the Nepal State Congress Party and the Bhutan State Congress Party.
The SSC's main constituents were immigrant Nepalese, while its opponent, the Sikkim National Party, had support among the aboriginal Bhutia and Lepcha people. It campaigned to change the election system from a confessional system to a "one man, one vote" system. When that reform happened in 1974, the numerically superior Nepalese made the Congress Sikkim's dominant political party.
Some anti-clerical and other modernizing elites within the Bhutia-Lepcha community joined the Sikkim State Congress, because of its desire to abolish landlordism. Kazi Lhendup Dorjee, one of these, was president of the party between 1953 and 1958. Subsequently, SSC merged with Sikkim Janata Party in 1972, forming the Sikkim Janata Congress.