And now he's reaching out to supporters for help in paying it off.
"We still have a little ground to make up on our campaign debt retirement," he wrote in an e-mail blast. "I would be incredibly appreciative if you could click here to donate $5 or more today!"
His opponent, Democrat Claire McCaskill who trounced Akin last month, also is in the hole. End-of-campaign reports show she owes about $240,000.
But as an elected official, she won't have as much trouble paying it off as Akin now will.
Records show that McCaskill raised $18.6 million for her re-election campaign. Akin raised $5.6 million.