Goodwood is one of the courses taking part in the offer
Free admission is to be offered at eight meetings during one week at the end of April in an attempt to attract new fans to horse racing.
The initiative is being organised by 'Racing for Change' as part of a wider campaign to broaden the sport's appeal.
Eight courses will open their gates for free over six days between Monday 26 April and Saturday 1 May.
Some of Britain's biggest racing venues such as Ascot, Goodwood, Kempton and Doncaster are taking part.
The fixtures will provide a mix of both afternoon and evening meetings, as well as a choice of racing over jumps or on the Flat.
The free-admission fixtures are:
• Monday, April 26 - Towcester and Wolverhampton
• Tuesday, April 27 - Sedgefield (evening)
• Wednesday, April 28 - Ascot and Kempton (evening)
• Thursday, April 29 - Huntingdon (evening)
• Friday, April 30 - Doncaster
• Saturday, May 1 - Goodwood
Towcester has long offered free admission and benefited from bigger crowds and increased revenue on betting and catering.
The promotion will be backed by a public relations drive at national and local level, and an advertising campaign on regional radio.
Racing for Change chairman Chris McFadden said: "These fixtures give the public a real choice. The quality of the racing is great.
"With three of the fixtures being in the evening and one on Saturday afternoon, they are at times that are convenient for people to come along with their families."
Ascot's meeting includes the Group Three Sagaro Stakes, while Goodwood has the Listed £40,000 Conqueror Stakes, and Sedgefield puts on its feature race of the year, the Durham National.
Some of the racecourses will limit the free admission to general enclosures.
At Goodwood, the complimentary offer is for the Gordon and Lennox enclosures, while at Ascot it is the grandstand that will have complimentary access.
The week is also to be used by Racing for Change to introduce a number of its trial initiatives announced at the beginning of the year, including a new display of photo-finish results on big screens and modernised raceday announcements.
It has not yet been announced when one of the most high-profile ideas, decimalised odds - rather than fractions - might be trialled.
Further details are likely to emerge when racing industry leaders meet for a conference on Tuesday.