The 85th Indianapolis 500 was held at the Indianapolis Motor Speedway in Speedway, Indiana on Sunday, May 27, 2001. Race rookie Hélio Castroneves, a three-year veteran of the CART series, led the final 52 laps and won his first Indy 500. Penske Racing swept 1st-2nd with Gil de Ferran the runner-up. Winning car owner Roger Penske scored his 11th victory at the Indianapolis 500, and his first-ever 1-2 finish in the race. It was a redemption from the team's previous attempt at Indy (1995) in which both of his cars failed to qualify; subsequently followed by a five-year absence (1996-2000) due to the open wheel "split."

The race was sanctioned by the Indy Racing League, and was part of the 2001 Indy Racing Northern Lights Series season. The 2001 race was notable in that several top CART teams returned to Indy for the first time since 1995, despite the ongoing open wheel "split." IRL-based teams excelled in time trials, taking the front row, and the top four starting positions overall. However, the CART-based teams swept the top six finishing positions on race day.

The race experienced two rain delays, one lengthy yellow flag around the midway point, and one brief red flag period later in the day. The race, however, was run to its full 500-mile distance.

In the seventh year of the IRL/CART split, Team Penske and Team Green broke ranks and returned to race at Indianapolis. Ganassi, who had returned in 2000, entered as well. After one year of retirement, two-time winner Arie Luyendyk returned to the cockpit. CART did not schedule any races the weekend of Indy 500 pole qualifying, nor the race itself, to allow teams the opportunity to participate without interference.

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