List of freshman class members of the 109th United States Congress Senate Senate

| State_ | Senator | Party | Switched_Party | Prior_background | Religion | Birth_year |
|---|---|---|---|---|---|---|
| Colorado | Ken Salazar | Democratic | Yes Open Seat; Replaced Ben Nighthorse Campbell | Attorney General of Colorado | Roman Catholic | 1955 |
| Georgia | Johnny Isakson | Republican | Yes Open Seat; Replaced Zell Miller | Member of the U.S. House of Representatives | United Methodist | 1944 |
| Illinois | Barack Obama | Democratic | Yes Open Seat; Replaced Peter Fitzgerald | Member of Illinois Senate | Christianity / United Church of Christ | 1961 |
| North Carolina | Richard Burr | Republican | Yes Open Seat; Replaced John Edwards | Member U.S. House of Representatives | Methodist | 1955 |
| Oklahoma | Tom Coburn | Republican | No Open Seat; Replaced Don Nickles | Former Member U.S. House of Representatives | Baptist | 1948 |
| South Carolina | Jim DeMint | Republican | Yes Open Seat; Replaced Ernest Hollings | Member U.S. House of Representatives | Presbyterian | 1951 |