Ohio State is the second team to hold the No. 1 spot in The Associated Press Top 25 this season.
The Buckeyes (18-0) moved up one spot to replace Duke, which was No. 1 in the preseason Top 25 and the first nine polls of the regular season, including six weeks as the unanimous pick of the 65-member national media panel.
The Blue Devils' loss at Florida State on Wednesday opened the way for the Buckeyes, who are No. 1 for the third time in school history. Ohio State was No. 1 for all of 1960-61 and 1961-62, a run of 27 straight polls, and for the last three weeks of 2006-07.
With West Virginia moving into the poll for the first time this season, the Big East ties its own record with nine teams in the Top 25. There were nine Big East teams ranked for one week in January 2009.
The Buckeyes received 49 first-place votes Monday. Kansas, which was No. 1 on six ballots, and Syracuse, which got eight first-place votes, each moved up one spot to second and third.
Duke, which still received one first-place vote, dropped to fourth. Pittsburgh, which was also No. 1 on one ballot, San Diego State and Villanova remained fifth through seventh.
Connecticut, BYU and Texas rounded out the top 10.
Fourteen ranked schools lost last week, including Purdue, Notre Dame and Illinois, which each lost twice.
The other schools moving into the poll this week are Minnesota and Michigan State, both of which were ranked earlier this season, and Saint Mary's, Calif.
Kansas State, which was No. 3 in the preseason poll, Temple, Georgia and UCF dropped out this week.
Ohio State, led by John Havlicek and Jerry Lucas, won the national championship in 1960 and lost the title game to Cincinnati in 1961 and 1962. The Buckeyes, this time led by Greg Oden and Mike Conley Jr., reached the Final Four in 2007, losing to Florida in the championship game.