David Nicholson Mares' Hurdle

The OLBG Mares' Hurdle (known as the David Nicholson Mares' Hurdle until 2011) is a Grade 1 National Hunt hurdle race in Great Britain which is open to mares aged four years or older. It is run on the Old Course at Cheltenham over a distance of about 2 miles and 4 furlongs (4,023 metres), and during its running there are nine hurdles to be jumped. The race is scheduled to take place each year during the Cheltenham Festival in March.

The winner's trophy for this event is named in memory of David Nicholson (1939–2006), who was successful as both a jockey and a trainer in National Hunt racing. Nicholson's record at the Cheltenham Festival included five victories as a jockey, and seventeen as a trainer.

This race was established in 2008, and in its inaugural year it was held on the final day of the Festival on Cheltenham's New Course. It was switched to the opening day on the Old Course in 2009. It was initially given Grade 2 status and was upgraded to Grade 1 status from the 2015 running.