These are the Billboard magazine number one albums of 1991, per the Billboard 200.
| Issue Date | Album | Artist(s) |
|---|---|---|
| January 5 | To the Extreme | Vanilla Ice |
| January 12 | ||
| January 19 | ||
| January 26 | ||
| February 2 | ||
| February 9 | ||
| February 16 | ||
| February 23 | ||
| March 2 | Mariah Carey | Mariah Carey |
| March 9 | ||
| March 16 | ||
| March 23 | ||
| March 30 | ||
| April 6 | ||
| April 13 | ||
| April 20 | ||
| April 27 | ||
| May 4 | ||
| May 11 | ||
| May 18 | Out of Time | R.E.M. |
| May 25 | Time, Love & Tenderness | Michael Bolton |
| June 1 | Out of Time | R.E.M. |
| June 8 | Spellbound | Paula Abdul |
| June 15 | ||
| June 22 | Niggaz4Life | N.W.A. |
| June 29 | Slave to the Grind | Skid Row |
| July 6 | For Unlawful Carnal Knowledge | Van Halen |
| July 13 | ||
| July 20 | ||
| July 27 | Unforgettable... with Love | Natalie Cole |
| August 3 | ||
| August 10 | ||
| August 17 | ||
| August 24 | ||
| August 31 | Metallica | Metallica |
| September 7 | ||
| September 14 | ||
| September 21 | ||
| September 28 | Ropin' the Wind | Garth Brooks |
| October 5 | Use Your Illusion II | Guns N' Roses |
| October 12 | ||
| October 19 | Ropin' the Wind | Garth Brooks |
| October 26 | ||
| November 2 | ||
| November 9 | ||
| November 16 | ||
| November 23 | ||
| November 30 | ||
| December 7 | Achtung Baby | U2 |
| December 14 | Dangerous | Michael Jackson |
| December 21 | ||
| December 28 |
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