United States congressional delegations from Connecticut

Since Connecticut became a U.S. state in 1788, it has sent congressional delegations to the United States Senate and United States House of Representatives, beginning with the 1st United States Congress in 1789. Each state elects two senators to serve for six years in general elections, with their re-election staggered. Prior to the ratification of the Seventeenth Amendment in 1913, senators were elected by the Connecticut General Assembly. Each state elects varying numbers of members of the House, depending on population, to two-year terms. Connecticut has sent five members to the House in each congressional delegation since the 2000 United States Census.

A total of 292 unique individuals have represented Connecticut in Congress; Connecticut has had 57 senators and 259 representatives, and 24 have served in both the House and the Senate. Nine women from Connecticut have served in the House, the first being Clare Booth Luce, while none have served in the Senate. Two African-Americans from Connecticut, Gary Franks and Jahana Hayes, have served in the House.

The current dean, or longest serving member, of the Connecticut delegation is Representative Rosa DeLauro of the CT's 3rd congressional district, who has served in the House since 1991. She is the longest-serving House member in Connecticut history, and the second longest-serving member of Congress from Connecticut, behind Chris Dodd, who served 36 years combined in the House and Senate. Dodd is also Connecticut's longest-serving senator.

Current delegation
Connecticut's current congressional delegation in the consists of its two senators and its five representatives, all of whom are Democrats. Connecticut has not had a Republican member of Congress for more than a decade, since Republican representative Chris Shays lost his race against Democrat Jim Himes in the state's 4th congressional district in 2008.

The current dean, or longest serving member, of the Connecticut delegation is Representative Rosa DeLauro of the CT's 3rd congressional district, who has served in the House since 1991. She is the longest-serving House member in Connecticut history, and the second longest-serving member of Congress from Connecticut, behind Chris Dodd, who served 36 years in total.

As of August 2023, the Cook Partisan Voting Index, a determination of how strongly partisan a state is, ranked all districts and senate races in Connecticut as solidly Democratic, except for the 5th House district, currently represented by Jahana Hayes, which was ranked as leaning Republican.

United States Senate
Senators Oliver Ellsworth, William S. Johnson, and Roger Sherman were Founding Fathers. Ellsworth helped write the Judiciary Act of 1789, and later served as Chief Justice of the United States Supreme Court. Uriah Tracy served as president pro tempore of the Senate from May 1800 to November 1800, James Hillhouse served as president pro tempore from February 1801 to December 1801, Lafayette Sabine Foster served as president pro tempore from March 1865 to March 1867, and Frank Brandegee served as president pro tempore from May 1912 to March 1913. Senator Orville Platt, along with Nelson Aldrich, William Allison, and John Coit Spooner, formed "The Senate Four", a group of powerful legislators who controlled much of the Senate's operations. Platt also helped draft the Platt Amendment. Senator Joseph Lieberman was the Democratic nominee for vice president in 2000.

Senators are elected every six years depending on their class, with each senator serving a six-year term, and elections for senators occurring every two years, rotating through each class such that each election, around one-third of the seats in the Senate are up for election. Connecticut's senators are elected in classes I and III. Currently, Connecticut is represented in the Senate by Richard Blumenthal and Chris Murphy.

United States House of Representatives
John Q. Tilson served as the House Majority Leader for the Republican party from 1925 to 1931. Barbara Kennelly was the first woman to become the Democratic chief deputy whip. Ella T. Grasso later became the first female governor elected in the United States.

From 1789 to 1837, representatives from Connecticut were elected from Connecticut's at-large congressional district, which was subsequently replaced with Connecticut's congressional districts. Connecticut has sent five members to the House in each congressional delegation since the 2000 United States Census. One member of the House of Representatives is sent from each district via a popular vote. Districts are redrawn every ten years, after data from the US Census is collected.

1789–1793: 5 seats
Connecticut was granted five seats in the House until the first US census in 1790.

1793–1823: 7 seats
Following the 1790 census, Connecticut was apportioned seven seats.

1823–1843: 6 seats
Following the 1820 census, Connecticut was apportioned six seats.

1843–1903: 4 seats
Following the 1840 census, Connecticut was apportioned four seats.

1903–1933: 5 seats
Following the 1900 census, Connecticut was apportioned five seats. The fifth seat was established at-large from 1901 to 1911, when it was converted into a fifth district via a redistricting plan.

1933–2003: 6 seats
Following the 1930 census, Connecticut was apportioned six seats. The sixth seat was established at-large from 1931 to 1964, when it was converted into a sixth district via a reapportioning plan.

2003–present: 5 seats
Following the 2000 census, Connecticut was apportioned five seats.