Significant prize money increases have been announced for Victorian racing, including boosts to the Melbourne Cup, Caulfield Cup and Cox Plate.

Victoria's three biggest horse races have had significant boosts as part of a $12.4 million prize money injection across the state.

Australia's most iconic race, The Melbourne Cup, increases by $1 million to $7.3 million this year while the Cox Plate and Caulfield Cup both increase $2 million to $5 million.

All country Cups will also share in prize money increases along with other increases at various levels of racing in the state.

Other feature races to receive a boost are the Victoria Derby which goes from $1.5 million to $2 million while the Moonee Valley Cup increases by $200,000 to $500,000.

"Our vision is 'Racing for All' and there is something for all owners, trainers and jockeys within these prize money increases which stretch from the Melbourne Cup to the Burrumbeet Cup," Racing Victoria's chief executive Giles Thompson said.

The winner of the Melbourne Cup now receives $4 million (plus $250,000 in trophies) with second earning $1 million, and third $500,000.

Prize money will be paid from first to 12th as part of the restructure for the Melbourne Cup, with sixth to 12th earning $150,000.

"It is the world's richest staying handicap and is backed by 158 years of history and tradition," Victoria Racing Club chairman Amanda Elliott said.

"Winning the great race is on every owner, breeder, trainer and jockey's bucket list, both locally and globally."

Champion Winx is expected to chase a record fourth-straight Cox Plate in October and the increase to $5 million makes the 2040m feature Australia's richest Group One weight-for-age race.

Sydney's $13 million The Everest (1200m), to be run for the second time this October at Randwick, does not hold Group One status.

"The prize money increase is a significant boost for our great club and our great race and it will ensure that our race remains at the pinnacle of Australian racing," Moonee Valley Race Club chairman Don Casboult said.

Invitations will go out next week to the best international middle-distance weight-for-age horses in a bid to attract them to take up the challenge at Moonee Valley.

"Over the coming years the club will continue to develop the international profile of the Cox Plate and we believe that prize money of $5 million will be very tempting to connections of those horses," Casboult said.

The Melbourne Racing Club's chief executive Josh Blanksby said it was an historic announcement for the club to have the Caulfield Cup a $5 million race.

"The Caulfield Cup is the world's pre-eminent turf handicap over the classic 2400-metre distance, a fact we are thrilled to have solidified by this enhancement," Blanksby said.