This is the 58th week at No. 1 all-time for the Jayhawks and their first trip to the top since February 2011.
Here's a look at some other tidbits in the AP Top 25 released Monday:
NO. 1 VS. NO. 2:
When Kansas and Oklahoma meet Monday night, it will be the 40th time the top two teams in the poll have played each other. The top-ranked teams have a 21-18 record.
The last time it happened was Nov. 12, 2013, when No. 2 Michigan State beat No. 1 Kentucky 78-74.
This was the 10th time two teams from the same conference met as Nos. 1 and 2 and it's the second time for Oklahoma and Kansas.
The Big Eight, the forerunner of the Big 12 which has Kansas and Oklahoma on Monday night, had two a month apart in 1990 when it was Oklahoma-Kansas and Missouri-Kansas.
Four schools moved into the Top 25 this week and three of them are in the poll for the first time this season.
No. 23 Connecticut was ranked in the preseason Top 25 and for the first two weeks of the regular season. The Huskies were then out for two weeks, back in for one and out again for the last two.
Cincinnati, which was No. 22, and Baylor, which was No. 23, both dropped out following one loss each last week. Utah, which was No. 21, and UCLA, which was No. 25, both lost two games on their opening weekend of Pac-12 Conference play.
There are three unbeaten Division I teams and they are sprinkled throughout the Top 25.
Iowa's big week and Xavier's big recoup have them leading the way this season with three wins each over ranked teams.
Xavier, which had already beaten then-No. 24 Michigan and then-No. 23 Cincinnati, rallied from its big loss to Villanova last week by beating No. 9 Butler on Saturday. The Musketeers dropped from No. 6 to ninth this week.
The addition of Pittsburgh gives the Atlantic Coast Conference the most ranked teams at six. Joining the Panthers in the Top 25 are Virginia, North Carolina, Miami, Duke and Louisville.
Three conferences - the Big 12, the Big Ten and the Big East - all have four ranked teams. The Southeastern Conference has three, while the American Athletic Conference has two and the Pac-12 and Atlantic 10 have one each.
In addition to Monday night's 1 vs. 2 matchup between Kansas and Oklahoma the only other game featuring two ranked teams this week is Sunday night's No. 11 Villanova at No. 18 Butler.