Stevens, the Senate's longest serving Republican, faces up to five years in prison for each count, the Associate Press reported, but would probably serve much less.
The trial centered on gifts, including $250,000 worth of renovations to his home, that Stevens failed to report on his 2001 Senate Financial Disclosure Form
Stevens spent three days defending himself on the witness stand, and tried to get the venue transferred to Alaska so he could campaign in a tough reelection fight against Democrat Mark Begich.
He must now either drop out of the race or continue campaigning as a convicted felon.
Much of the trial hinged on the testimony of oil company CEO Bill Allen, the senator's longtime friend, who testified that his employees dramatically remodeled the senator's home, and that even though he never sent the Stevens a bill, the senator knew he was getting a deal on the renovations.
Earlier in the trial, Justice Department prosecutors admitted a serious evidence mistake when they failed to share part of Allen's testimony in which he said he believed Stevens and his wife would have paid for the renovations to their home in Alaska if Allen had sent them a bill.
The judge ordered the prosecutors to turn over to the defense all FBI interviews with witnesses without any redactions.
Allen's workers installed a generator at Stevens' house in 1999 after the senator asked him for one in case he lost power because of the millennium computer bug. Allen said the generator cost about $6,000.
That year, the senator also asked him to swap cars. Allen testified that he gave Stevens a new $44,000 Land Rover in exchange for a rare "1964 1/2" Mustang worth around $20,000. Stevens also gave Allen a $5,000 check, the former executive testified.
Stevens, 84, has been part of Alaska politics since before statehood, and was much beloved for sending home billions of dollars in federal money for projects and state programs.
If he wins re-election, he can continue to hold his seat because there is no rule barring felons from serving in Congress, the AP reported. The Senate could vote to expel Stevens on a two-thirds vote.
"Put this down: That will never happen -- ever, OK?" Stevens said in the weeks leading up to his trial. "I am not stepping down. I'm going to run through and I'm going to win this election."