When Del Mar opened in 1937, Bing Crosby was at the gate to personally greet the fans. On August 12, 1938, the Del Mar Thoroughbred Club hosted a $25,000 winner-take-all match race between Charles S. Howard's Seabiscuit and the Binglin Stable's colt, Ligaroti. In an era when horse racing ranked second in popularity with Americans to Major League Baseball, the match race was much written and talked about and was the first nationwide broadcast of a Thoroughbred race by NBC radio.  In the race, Seabiscuit was ridden by jockey George Woolf and Ligaroti by Noel Richardson. In front of a record crowd that helped make the fledgling Del Mar race track a success, Seabiscuit won an exciting battle by a nose.

By 1940, Del Mar became a summer playground for many Hollywood stars. Between 1942 and 1944 the facility was closed due to the Second World War. Initially, the grounds were used for training by the United States Marine Corps, then as a manufacturing site for parts to B-17 bombers.

The first Bing Crosby Stakes was held at Del Mar in 1946 and that same year the Santa Fe Railroad began offering a racetrack special bringing spectators, bettors and horses to Del Mar from Los Angeles. Throughout the late 1940s and 1950s the track became the Saratoga of the West for summer racing. The track had large purses for many stakes, many of the stakes races were won by the legendary jockey, Bill Shoemaker.

Throughout the 1960s and 1970s Del Mar continued to offer high quality racing and continued to be one of the premier racetracks in the country. The track attempted to run a fall meet in the 1960s but later canceled it after getting lackluster results. This allowed for the creation of the Oak Tree Racing Association at Santa Anita race track.

Change marked the 1980s when the infield was opened to spectators and in 1984 Trevor Denman became the voice of Del Mar. The track still offered the best summer racing in the West and continued to grow in purses, handle and attendance.

Aerial view of the Del Mar Fairgrounds and Racetrack looking northwest along the Pacific Ocean coastline.

In the 1990s the track underwent a major renovation. The grandstand of the Del Mar Fairgrounds was demolished and replaced. In 1991 the track ran its richest race to date, the $1,000,000 Grade I Pacific Classic Stakes. The first Classic was won by an impressive three-year-old named Best Pal.

Beginning in the year 2000, the Del Mar Thoroughbred Club 's marketing team went through a major shift in their marketing direction. They realized they had to attract a more youthful audience as well as a female audience. They focused Del Mar as a fashionable destination, using social media and other avenues to market the racetrack. The majority of ads didn't show horses. They adopted the slogan "Cool as Ever" and created a new brand around "Del Mar Scene". They also hired jockey and model Chantal Sutherland to be the new face of the Del Mar Thoroughbred Club.

Their strategy worked as over 13 years later Del Mar has changed their demographics and audience attendance.  The marketing campaign of the Del Mar Racetrack has become a Stanford business study to see if their strategy could be done at other racetracks.

One of the largest draws each year for the Del Mar racetrack has now become Opening Day with their famous hats contest and parties. 

In March 2013, there was a vote to expand the turf portion of the racetrack.  Construction began later in the year and the work was completed in time for the 2014 racing season. The work included widening the course to 80 feet and softening the curve coming out of the diagonal chute, thus allowing more horses to compete in turf races.  The following year Del Mar renovated the main track installing El Segundo Sand.

Starting in 2014, Del Mar is expected to run more racing cards due to the closure of Hollywood Park Racetrack.  A fall meet was added, featuring the Hollywood Turf Cup Stakes, Hollywood Derby and Matriarch Stakes. Del Mar will host the Breeders' Cup for the first time in the fall of 2017.

The Del Mar racetrack runs live racing July through early September. A second live racing meet runs in November to mid-December starting in 2014.  The other months of the year the satellite wagering facility is operating at the fairgrounds.