Maxwell Warburn Long (October 16, 1878 – March 4, 1959) was an American athlete, winner of 400 m at the 1900 Summer Olympics.
Having won three AAU titles from 1898 to 1900 and IC4A title in 1899 in 440 yd (402 m), 1899 an AAU title in 220 yd (201 m) and 1900 an AAU title in 100 yd (91 m), Maxie Long from Columbia University, was one of the top favourites for the Olympic title in Paris.
In Paris, Long led the race from start to finish, beating his team-mate William Holland at 3 yards (2.7 m).
Later in this year, Long ran some brilliant records. On September 29 he ran 47.8 for 440 yd (402 m) and a few days later even 47.0, but the latter was on a straight track.