This table, organized by Congress, lists all new senators as they begin Senate service. For statistical information about freshmen senators, see Senate Freshmen Since Direct Election (1914).

1.  Chris Coons, Joe Manchin III, and Mark Kirk are considered freshmen senators in the 112th Congress even though they began Senate service during the lame duck session of the 111th Congress.

2.  Previously served in the Senate

3.  Took the oath of office on January 22, 2009.

4.  Elected in the 2008 general election; however, seat remained vacant until the election outcome was resolved by the Minnesota Supreme Court.

5.  Took the oath of office on September 25, 2009.

6.  Elected in both the 2010 special and general elections.

7.  James Talent, John Cornyn, and Lisa Murkowski were counted as new senators in the 108th Congress even though they began their Senate service in late 2002. Their Senate service began after the Senate had adjourned sine die for the 107th Congress.

8.  Previously served in the Senate

9.  Appointed to fill the vacancy caused by the death of Mel Carnahan, who was posthumously elected in the 2002 general election.

10.  Elected in the November 2002 general election for a full term beginning January 3, 2003, and subsequently appointed to fill the vacancy in the term ending January 3, 2003, caused by the resignation of Phil Gramm. No seniority was gained for Cornyn ahead of incoming new senators for the 108th Congress, per a 1980 Rules Committee policy. The Senate was not in session, as it had adjourned sine die.