Leonian's interest in motion photography found a great outlet when photographing horses.

Several of his images of race horses were used by Aqueduct Racetrack and the Racing Association of America to promote horse racing. He also photographed at the Marlboro Cup Invitational and the Belmont Stakes, as well as harness racing at Roosevelt Raceway, horse shows at Fairfield, Ox Ridge, and Piping Rock, the Blind Brook polo team, and the USA Pentathlon for Sports Illustrated in 1968. 

Pentathalon 1968 © Phillip Leonian

Big A © 1964 Phillip Leonian

Equestrian blue jacket © 1964 Phillip Leonian

Great Escape © 1964 Phillip Leonian

Harness Racer in a Red Blanket © 1966 Phillip Leonian

Trotter © 1966 Phillip Leonian

Trussed Up © 1966 Phillip Leonian

Beaupy Racing © 1964 Phillip Leonian

Rainy Day at Saratoga © 1964 Phillip Leonian

Cantering Thoroughbred © 1964 Phillip Leonian

Equestrian with Red Jacket © 1964 Phillip Leonian

Harness Racer Head On © 1966 Phillip Leonian

US Equestrian Team © 1968 Phillip Leonian

White horse equestrian © 1958 Phillip Leonian

Winners Spotlight © 1966 Phillip Leonian