The 2008–09 Big Ten Conference men's basketball season marked the continuation of the annual tradition of competitive basketball among Big Ten Conference members that began in 1904. It was the 104th season of Big Ten Conference basketball play. Although during the 2008-09 NCAA Division I men's basketball season there were no Big Ten players named to any All-American teams, no coaches given any national coaching honors, and no teams that won any major preconference tournament, the season was successful for other reasons. The conference had an overall 14–8 record in postseason play with one team reaching for the 2009 NCAA Men's Division I Basketball Tournament championship game and another winning the championship of the 2009 National Invitation Tournament (NIT).

The season marked the second year that all regular season and Big Ten Conference men's basketball tournament games were nationally televised. It was the first season that eight member teams achieved 20 wins. During the season, the conference achieved a .781 winning percentage against non-conference opponents, which is the highest percentage since 1998–99.

Michigan State was the regular season champion winning the league four games. Purdue and Illinois tied for second place. Michigan State's Kalin Lucas was named Big Ten Player of the Year. Michigan State's Tom Izzo was named Coach of the Year by the coaches while Penn State's Ed Dechellis was named Coach of the Year by the media.

Purdue won the Big Ten tournament by defeating Ohio State in the championship. As a result of its win, Purdue received the conference's automatic bid to the NCAA tournament. In total, seven teams received bids to the NCAA tournament: Michigan State, Purdue, Illinois, Ohio State, Michigan, Minnesota, and Wisconsin. By placing 7 of its 11 teams in the tournament, it had 64% of its teams in the tournament, which outpaced all other conferences. Both Michigan State and Purdue advanced to the second weekend's Sweet Sixteen round, where Purdue lost to Connecticut. Michigan State advanced to the championship game where it lost to North Carolina 89–72.

The Big Ten also had two entrants in the 2009 NIT: Penn State and Northwestern with Penn State winning the tournament.

Preseason

All-Big Ten players On October 26, the Big Ten media selected Purdue as the preseason top team. It selected Michigan State and Wisconsin as second and third respectively. However, the November 10 national AP Poll and Coaches' Poll ranked Michigan State as the highest among Big Ten teams with Purdue second and Wisconsin third in their respective preseason 2008–09 NCAA Division I men's basketball rankings.

The media also made preseason All-Big Ten player selections: Manny Harris, sophomore guard from Michigan, Raymar Morgan, junior forward from Michigan State, Marcus Landry, senior forward from Wisconsin, E'Twaun Moore, sophomore guard from Purdue, and Robbie Hummel, sophomore forward from Purdue, who was named Preseason Player of the Year.

The Los Angeles Athletic Club released its annual preseason John R. Wooden Award watch list on November 13. The list was composed of 50 student athletes who, based on 2007–08's individual performance and team records, were the early frontrunners for college basketball's most coveted trophy. These top 50 candidates were returning players. Transfers, freshmen, and medical red-shirts were not eligible for this preseason list, but were evaluated and considered for both the Midseason Top 30 list and the National Ballot. The Big Ten was represented by Purdue's Hummel, Wisconsin's Landry and Michigan State's Morgan.

On December 18, the Atlanta Tipoff Club released its annual early season Naismith College Player of the Year award watch list. The top-50 list included Hummel, Moore and Morgan. The watch list does not include incoming freshmen, although those student-athletes were considered in the February 2009 mid season vote.

Regular season November The Big Ten began the season anticipating competitive schedules since the conference had scheduled appearances against thirteen of the teams appearing in both of the major pre-season rankings. The conference opened its first week with a 14–0 record, while holding all 14 opponents to 65 points or less. By the end of the second week of the season the Big Ten found itself with the best non-conference record in the nation at 35–1. They became the first power conference (ACC, Big 12, Big East, Big Ten, Pac-10 or SEC) to have a road win against another of the conferences when Illinois bested Vanderbilt on November 20. On the same date, Michigan achieved the conference's first victory against a top five opponent since Michigan State upended Texas on December 22, 2007. Big Ten teams did not win any of the larger preconference tournaments: Purdue lost in overtime of the November 28 championship game of the 16-team 2008 NIT Season Tip-Off tournament, Michigan placed second in the 16-team 2K Sports Classic benefiting Coaches vs. Cancer tournament on November 21, and Wisconsin was runner up in the 8-team Paradise Jam Tournament on November 24. Minnesota, was successful in the 4-team National Association of Basketball Coaches Classic with a win over Georgia State Panthers in the championship game.

December On Wednesday, December 3, The Big Ten lost to the Atlantic Coast Conference for the 10th consecutive year in the ACC–Big Ten Challenge. The final margin was 6–5. By the end of the fourth week of the season in early December, the Big Ten had the highest percentage of teams receiving votes in the Associated Press National Rankings and had the highest non-conference strength of schedule in the Ratings Percentage Index (RPI). Minnesota's 8–0 start was Tubby Smith's first. After five weeks, the Big Ten had the maintained its AP rankings leadership, but also took over the overall leadership in the RPI ratings. The conference's 82–19 record included only losses to teams that had advanced to the post-season the year before. Michigan State's win against Texas gave the Big Ten half of the nation's first six victories over top five teams. National Invitation Tournament defending champion, Ohio State's eighth victory gave them the nation's longest win streak at thirteen. Entering conference play, at 12–0 Minnesota remained one of the nine unbeaten teams in the nation, which was its best start since 1948–49. The conference had one of three winning conference records on the road against non-conference opponents at 10–8 and with 5 of its 11 teams ranked in the AP poll, it had the highest percentage of its teams ranked.

January For the first time since freshmen became eligible in 1974, Indiana started four freshmen in a conference opener on January 3 against Iowa. On January 11, Minnesota tied an NCAA record and set a conference record by making all nine of its three-point field goals. Illinois' January 14 victory over Michigan made it the thirteenth team in NCAA Division I history and second (after Indiana) in the Big Ten to achieve 1600 wins. On January 21, Northwestern snapped the third-longest home-court winning streak in the nation when it stopped Michigan State from earning its 29th straight home victory. John Beilein recorded his 500th win as head coach of a four-year school and 575th win overall on January 24 against Northwestern. As January ended, the conference enjoyed its fourth consecutive week as the leader in the RPI strength of schedule. On January 31, Matt Roth became the first Indiana Hoosier, first Big Ten freshman and third Big Ten player to record nine three-point shots in a single game.

February At the midpoint of the conference schedule at the beginning of February, the Big Ten had the highest Sagarin Rating central mean score. Previously, Michigan State had never won its first five conference road games since joining the Big Ten for the 1950–51 season, but during the season, they were one of the last two teams to be undefeated on the road at 7–0. Tubby Smith became the third coach in NCAA history to record 20 wins during 16 consecutive seasons. Through its 166th contest, the Big Ten, which had led the nation in average attendance for the prior 32 years, surpassed two million in attendance for the sixteenth consecutive season and eighteenth overall.

Attendance The big ten concluded the season with the highest attendance in the nation for the 33rd straight season with an average attendance of 12,519 fans per game/session, including regular-season games and conference tournament sessions. This surpassed the SEC, which was second with an 11,625 average. The Big Ten held seven of the top 25 places among individual institutions, while no other conference had more than four individual schools among the top 25.

Rankings

AP Poll Pre Wk1 Wk2 Wk3 Wk4 Wk5 Wk6 Wk7 Wk8 Wk9 Wk10 Wk11 Wk12 Wk13 Wk14 Wk15 Wk16 Wk17 Wk18 Final^ Illinois RV RV RV RV RV RV RV RV 25 19 23 22 18 20 23 RV RV RV Indiana Iowa Michigan RV RV RV RV 24 22 RV 25 RV RV Michigan State 6 5 5 13 18 19 11 10 8 7 7 9 13 9 6 9 8 6 8 2 Minnesota RV RV 23 21 22 18 21 RV 19 RV RV RV Northwestern RV RV Ohio State RV RV RV RV 21 17 15 24 RV RV RV RV 24 RV RV RV RV Penn State RV RV RV RV Purdue 11 11 10 9 14 13 10 9 14 19 18 16 12 20 19 16 19 24 17 14 Wisconsin 25 25 25 RV RV RV RV RV RV RV RV ^Final Poll = ESPN/USA Today Coaches Poll

Preconference schedules

Tournaments No Big Ten teams won any major early conference tournaments.

ACC–Big Ten Challenge DateTimeACC teamBig Ten teamLocationTelevisionAttendanceWinnerChallengeleader Mon., Dec 1 7:00PM Virginia Tech#22 Wisconsin Cassell Coliseum • Blacksburg, VA ESPN2 9,847 Wisconsin (74–72) BigTen (1–0) Tue., Dec 2 7:00PM Boston CollegeIowa Conte Forum • Chestnut Hill, MA ESPNU 4,084 Boston College (57–55) Tied (1-1) 7:00PM #22 Miami (FL)Ohio StateBankUnited Center • Coral Gables, FL ESPN 5,870 Ohio State (73–68) BigTen (2–1) 7:30PM Clemson Illinois Assembly Hall • Champaign, IL ESPN2 14,741 Clemson (76–74) Tied (2-2) 9:00PM #4 Duke#10 Purdue Mackey Arena • West Lafayette, IN ESPN 14,123 Duke (76–60) ACC (3–2) 9:30PM Virginia Minnesota Williams Arena • Minneapolis, MN ESPN2 12,424 Minnesota (66–56) Tied (3-3) Wed., Dec 3 7:15PM #17 Wake ForestIndiana LJVM Coliseum • Winston-Salem, NC ESPN 12,445 Wake Forest (83–58) ACC (4–3) 7:30PM MarylandMichigan Comcast Center • College Park, MD ESPNU 17,950 Maryland (75–70) ACC (5–3) 7:30PM Georgia Tech Penn StateAlexander Memorial Coliseum • Atlanta, GA ESPN2 7,900 Penn State (85–83) ACC (5–4) 9:15PM #1 North Carolina#12 Michigan State Ford Field • Detroit, MI(Basketbowl II) ESPN 25,267 North Carolina (98–63) ACC (6–4) 9:30PM Florida StateNorthwestern Welsh-Ryan Arena • Evanston, IL ESPN2 3,537 Northwestern (73–59) ACC (6–5) Game Times in EST. Rankings from ESPN Coaches Poll (Dec. 1). North Carolina State did not play due to its last place finish in the ACC during the 2007–2008 season.

In-season honors Players of the week Throughout the conference regular season, the Big Ten offices named a player of the week each Monday. Week Player of the week 11/17/08 Manny Harris, MICH 11/24/08Craig Moore, NU Talor Battle, PSU12/1/08 Mike Tisdale, ILL E'Twaun Moore, PUR 12/8/08 Evan Turner, OSU 12/15/08 Robbie Hummel, PUR 12/22/08 Robbie Hummel, PUR 12/29/08 Trent Meacham, ILL DeShawn Sims, MICH 1/5/09 Raymar Morgan, MSU 1/12/09 Kalin Lucas, MSU 1/19/09 William Buford, OSU 1/26/09 Kevin Coble, NU Jamelle Cornley, PSU 2/2/09 Evan Turner, OSU 2/9/09 Evan Turner, OSU 2/16/09 Joe Krabbenhoft, WIS Delvon Roe, MSU 2/23/09 Jake Kelly, IA 3/2/09 Michael Thompson, NU 3/9/09 Jake Kelly, IA

Midseason watch lists