The three biggest races of Perth's summer carnival will carry prize money of $1 million each.

The Kingston Town Classic, the Railway Stakes and Winterbottom Stakes, the only Group One races on the West Australian calendar, have received a prize money boost while the WA Guineas has been lifted to $500,000.

The Winterbottom, Railway and WA Guineas will be part of Perth's richest race day on November 21 with $3 million on offer on a nine race program.

The Kingston Town Stakes, up from $500,000 last year, is Perth's premier weight-for-age race over 1800m and will be run on December 5.

Racing and Wagering West Australia thoroughbred racing manager David Hunter said the increase was not only a boost for local owners but something that would help promote further interstate participation.

"It is imperative that we attract the best field possible if we are to maintain the Group One status on these important races," Hunter said.

The Chris Waller trained Moriarty was successful in the Kingston Town Stakes last year with local gallopers Magnifisio and Elite Belle Belle won the Winterbottom and Railway Stakes respectively.