Record*: 74-56, .569 W-L% (2nd of 11) (Schedule and Results)
*W-L-T adjusted to 65-56 by NCAA.
SRS: 6.74 (2nd of 11) ▪ SOS: 4.37 (3rd of 11)
Conference Champion: Michigan, Ohio State and Wisconsin
Ranked in Preseason AP Poll: 5 (Michigan, Michigan State, Ohio State, Penn State and Wisconsin)
Ranked in Final AP Poll: 5 (Michigan, Ohio State, Penn State, Purdue and Wisconsin)
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
|---|---|---|---|---|---|---|---|---|
| 1 | Sep 26, 1998 | Sat | Iowa | 37 | @ | Illinois | 14 | |
| 2 | Sep 26, 1998 | Sat | Michigan | 29 | Michigan State | 17 | ||
| 3 | Sep 26, 1998 | Sat | (14) Wisconsin | 38 | Northwestern | 7 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 4 | Oct 3, 1998 | Sat | Illinois | 13 | @ | Northwestern | 10 | |
| 5 | Oct 3, 1998 | Sat | (25) Michigan | 12 | @ | Iowa | 9 | |
| 6 | Oct 3, 1998 | Sat | (1) Ohio State | 28 | (7) Penn State | 9 | ||
| 7 | Oct 3, 1998 | Sat | Purdue | 56 | Minnesota | 21 | ||
| 8 | Oct 3, 1998 | Sat | (13) Wisconsin | 24 | @ | Indiana | 20 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 9 | Oct 10, 1998 | Sat | Iowa | 26 | Northwestern | 24 | ||
| 10 | Oct 10, 1998 | Sat | Michigan State | 38 | Indiana | 31 | ||
| 11 | Oct 10, 1998 | Sat | (1) Ohio State | 41 | @ | Illinois | 0 | |
| 12 | Oct 10, 1998 | Sat | (13) Penn State | 27 | @ | Minnesota | 17 | |
| 13 | Oct 10, 1998 | Sat | (12) Wisconsin | 31 | Purdue | 24 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 14 | Oct 17, 1998 | Sat | Indiana | 14 | Iowa | 7 | ||
| 15 | Oct 17, 1998 | Sat | Michigan | 12 | @ | Northwestern | 6 | |
| 16 | Oct 17, 1998 | Sat | (1) Ohio State | 45 | Minnesota | 15 | ||
| 17 | Oct 17, 1998 | Sat | (12) Penn State | 31 | Purdue | 13 | ||
| 18 | Oct 17, 1998 | Sat | (9) Wisconsin | 37 | @ | Illinois | 3 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 19 | Oct 24, 1998 | Sat | Michigan | 21 | Indiana | 10 | ||
| 20 | Oct 24, 1998 | Sat | Minnesota | 19 | Michigan State | 18 | ||
| 21 | Oct 24, 1998 | Sat | (1) Ohio State | 36 | @ | Northwestern | 10 | |
| 22 | Oct 24, 1998 | Sat | Purdue | 42 | Illinois | 9 | ||
| 23 | Oct 24, 1998 | Sat | (9) Wisconsin | 31 | @ | Iowa | 0 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 24 | Oct 31, 1998 | Sat | (22) Michigan | 15 | @ | Minnesota | 10 | |
| 25 | Oct 31, 1998 | Sat | Michigan State | 29 | Northwestern | 5 | ||
| 26 | Oct 31, 1998 | Sat | (1) Ohio State | 38 | @ | Indiana | 7 | |
| 27 | Oct 31, 1998 | Sat | (10) Penn State | 27 | Illinois | 0 | ||
| 28 | Oct 31, 1998 | Sat | Purdue | 36 | Iowa | 14 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 29 | Nov 7, 1998 | Sat | Illinois | 31 | Indiana | 16 | ||
| 30 | Nov 7, 1998 | Sat | (22) Michigan | 27 | (9) Penn State | 0 | ||
| 31 | Nov 7, 1998 | Sat | Michigan State | 28 | @ | (1) Ohio State | 24 | |
| 32 | Nov 7, 1998 | Sat | Purdue | 56 | @ | Northwestern | 21 | |
| 33 | Nov 7, 1998 | Sat | (8) Wisconsin | 26 | Minnesota | 7 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 34 | Nov 14, 1998 | Sat | Indiana | 20 | Minnesota | 19 | ||
| 35 | Nov 14, 1998 | Sat | (15) Michigan | 27 | (8) Wisconsin | 10 | ||
| 36 | Nov 14, 1998 | Sat | (7) Ohio State | 45 | @ | Iowa | 14 | |
| 37 | Nov 14, 1998 | Sat | (19) Penn State | 41 | Northwestern | 10 | ||
| 38 | Nov 14, 1998 | Sat | Purdue | 25 | @ | Michigan State | 24 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 39 | Nov 21, 1998 | Sat | Michigan State | 41 | Illinois | 9 | ||
| 40 | Nov 21, 1998 | Sat | Minnesota | 49 | Iowa | 7 | ||
| 41 | Nov 21, 1998 | Sat | (7) Ohio State | 31 | (11) Michigan | 16 | ||
| 42 | Nov 21, 1998 | Sat | Purdue | 52 | Indiana | 7 | ||
| 43 | Nov 21, 1998 | Sat | (13) Wisconsin | 24 | (16) Penn State | 3 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 44 | Nov 28, 1998 | Sat | (23) Penn State | 51 | Michigan State | 28 |