This is a complete list of all people who previously served in the United States Senate. As of January 2021, a total of 1,994 different persons have served in the Senate (including those currently serving). In the party affiliation column, if a senator switched parties and served non-consecutive terms, their affiliation for each term is listed on the corresponding line. If one of these senators also served multiple non-consecutive terms with the same party, a quotation mark indicates that their affiliation did not change between that term and their preceding term.