The United National Congress (abbr. UNC or UNCTT) is one of two major political parties in Trinidad and Tobago and the current parliamentary opposition. The UNC is a centre-left party. It was founded in 1989 by Basdeo Panday, a Trinidadian lawyer, economist, trade unionist, and actor after a split in the ruling National Alliance for Reconstruction (NAR). After spending six years in opposition, the UNC won control of the government in 1995, initially in coalition with the NAR and later on its own. In the 2000 general election, the UNC won an absolute majority in the Parliament. In 2001, a split in the party caused the UNC to lose its parliamentary majority and control of the government. From 2001 to 2010, the UNC was once again Parliamentary Opposition party. In May 2010, the UNC returned to government as the majority party in the People's Partnership. The UNC's Political Leader, Kamla Persad-Bissessar, was sworn in as the first female Prime Minister of Trinidad and Tobago.

The party symbol is the sun rising above the Trinity Hills. Historically, the UNC has been supported by a majority of Indo-Trinidadians and Tobagonians, especially Hindu Indo-Trinidadian and Tobagonians, thus it is colloquially called the Indian Party or the Hindu Party. The Spiritual Baptist and other racial and religious minorities of the country also support the party.

In opposition since the 2015 general election, the party holds 19 out of 41 Members of Parliament in the House of Representatives and 6 out of 31 members of the Senate, as mandated by the Constitution of Trinidad and Tobago to the official parliamentary opposition. The party has 67 out of the 139 local councillors and is in control of 7 of the 14 regional corporations since the 2019 Trinidadian local elections. The party has no representation in the Tobago House of Assembly.

As of December 2020, the UNC has 120,000+ registered members.