Syracuse, off to the best start in school history, is the first unanimous No. 1 in The Associated Press poll since Duke was for six weeks in 2010-11.
The Orange (21-0) are on top of the poll for the first time since a six-week run in 2011-12. They received all the first-place votes Monday from the 65-member national media panel.
Arizona (21-1) and Syracuse, which had been 1-2 for the past eight weeks, switched places after the Wildcats lost at California on Saturday.
"We're happy to be No. 1," coach Jim Boeheim said Monday. "Obviously, it's taken a lot of hard work. It's an honor. We'll try to keep playing well."
This is the 15th week Syracuse has been No. 1, tying DePaul and Massachusetts for 17th place all time.
Syracuse is the fourth team to hold the No. 1 ranking this season after Kentucky, Michigan State and Arizona.
Florida, Wichita State (the only other unbeaten in Division I) and San Diego State remained third through fifth and were followed by Villanova, Cincinnati, Kansas, Michigan State and Michigan. Texas made the biggest jump inside the Top 25 this week, moving from 25th to 15th.
The Longhorns (17-4) are on a six-game winning streak. The past four wins have been against teams that were ranked at the time: No. 8 Iowa State, No. 22 Kansas State, No. 24 Baylor and No. 6 Kansas. Add in their early season win over then-No. 14 North Carolina and the Longhorns have five wins over ranked teams.
Kansas leads this season with six wins over Top 25 teams, followed by No. 16 Iowa State and Texas with five.
Virginia, 24th in the preseason poll, stayed in the Top 25 for the first two weeks of the regular season and dropped out until this week. The Cavaliers have won five straight, including Sunday's buzzer-beating win at Pittsburgh, and are alone in second in the ACC behind Syracuse.
Connecticut was No. 18 in the preseason poll and stayed in the rankings for the next nine weeks, reaching as high as No. 9. The Huskies have won six of seven since losing consecutive road games to Houston and SMU.
Gonzaga, 15th in the preseason Top 25, stayed in the poll for 10 weeks with the Bulldogs reaching as high as No. 11. They have won six straight and already have a three-game lead in the West Coast Conference.
The Big 12 stayed on top of the conference race with five ranked teams, but there was change after that.
The ACC and American Athletic Conference both gained one team this week and are tied with four teams each in the poll. The Big Ten fell to fourth with three ranked teams.
Ohio State, which was 11th in the preseason poll and had a five-week run at No. 3, dropped out having lost five of seven after starting the season 15-0. The Buckeyes had been ranked in the past 80 polls, which was the third-longest active streak behind Duke (130) and Kansas (98). Ohio State's run started in January 2010.
Wisconsin was 20th in the preseason poll, and the Badgers spent five weeks at No. 4 and one at No. 3, compiling a 16-0 record before their current run of five losses in six games. Wisconsin had been in the past 19 polls.
UMass, which had reached as high as 13th, dropped out after losing three of four.
There are four games between ranked teams this week and two newcomers are involved.
On Monday, No. 16 Iowa State is at No. 19 Oklahoma State, which has lost three of four and fell 11 spots in this week's poll.
On Thursday, No. 22 UConn visits No. 7 Cincinnati. The American-leading Bearcats gained six poll positions this week.
Information from The Associated Press was used in this report.