OLBG Mares' Hurdle
The OLBG Mares' Hurdle, or OLBG.com Mares' Hurdle, is the sponsored title of the following horse races run in Great Britain;

Yorkshire Rose Mares' Hurdle, a Grade 2 race run at Doncaster Racecourse in January or February
David Nicholson Mares' Hurdle, a Grade 1 race run at Cheltenham Racecourse in March