1991 Major Indoor Lacrosse League season

The 1991 season is the 5th season of the league that began on December 29, 1990, and concluded with the championship game on April 6, 1991.

Team movement
No teams were added, removed, or relocated in the 1991 season. However, the MILL did divide the six teams into two divisions: Detroit, Pittsburgh, and New England comprised the National Division, and the American Division was Baltimore, New York, and Philadelphia.

All Star Game
The first-ever MILL All-Star Game was held at the Spectrum in Philadelphia during the 1991 season. The National Division defeated the American Division 25-20.

Championship
Detroit 14 @ Baltimore 12

All-Pro Teams
First Team:
 * John Conley, Philadelphia
 * Gary Gait, Detroit
 * Paul Gait, Detroit
 * Rick Sowell, Baltimore
 * John Tucker, Philadelphia
 * Ted Sawicki, Detroit (goalie)

Second Team:
 * Jeff Jackson, Baltimore
 * Butch Marino, Pittsburgh
 * Mike Cummings, New York
 * John Nostrant, Philadelphia
 * Brian Nikula, Pittsburgh
 * Sal LoCascio, New York (goalie)

Statistics leaders
Bold numbers indicate new single-season records. Italics indicate tied single-season records.

Attendance
10,814 were in attendance at Baltimore Arena to see the visiting Detroit Turbos defeat the Baltimore Thunder in the championship game.