The 2011–12 Ranji Trophy season is the 78th Ranji trophy season. It is being contested through two leagues: Super and Plate. Each division is divided into 2 groups – A and B, each team plays all the other teams from its group only once either home or away.

The Super League is divided into two groups of eight and seven teams, while the Plate League is divided into two groups of six teams each. The top two from each Plate sub-group contest semi-finals; the winners of these two matches then join the top three from each Super League sub-group in an eight-team knock-out tournament. The winner of this knock-out tournament then wins the Ranji Trophy. Knock-out matches are decided on the first innings result if the result is a draw.

Points in the league stages of both divisions are awarded as follows:

note^* – If match ends in a draw.

Super league – Group A

Super League – Group B

Plate League – Group A

Plate League – Group B