Tressel, 57, signed a deal with Ohio State in 2008 that had him under contract until January 2013. The new contract extends the agreement for two years.
"We wanted to reward Jim for his exemplary work with our football program and lock him in as our coach for an additional two years," Ohio State Director of Athletics Gene Smith said.
However, there was no pay raise for Tressel, who was already the highest paid coach in the Big Ten Conference and fifth highest in the country. The Columbus Dispatch said Tressel is paid $3.5 million a season.
The Buckeyes were 11-2 last season, winning the Big Ten title and the Rose Bowl. Tressel has built a 94-21 record since becoming the Ohio State coach in 2001. Ohio State won the Bowl Championship Series title game in 2002 and has been in the championship game two other times.
Perhaps most important to Ohio State fans, the Buckeyes are 8-1 against Michigan in that span.