Stevens, convicted of failing to report millions in gifts on Senate disclosure forms, said his philosophy has been "to hell with politics, just do what's right for Alaska. I've tried every day to live up to those words."
Stevens conceded to his successor, Democrat Mark Begich, the mayor of Anchorage, who was declared the winner this week after Alaskan election officials began counting absentee and provisional ballots.
"I feel blessed by God to have served in this body," Stevens said, adding he feels the same way now as he did when he was first elected in 1968. "When Alaska needed a strong voice ... I did the best I could."
He said he doesn't have a "rear-view mirror," and still envisions a day when he will be cleared of the felony charges.
"I yield the floor for the last time," he said.
His comments were followed by a lengthy standing ovation by other senators in the chamber.
Stevens is the longest serving Republican in the Senate. He has been a member of the Senate since Dec. 24, 1968.