The first season follows the lives of four high school classmates from Manhattan.
Blair also appeared as socialite Kris Jenner in the first season of FX true crime anthology series American Crime Story (2016).
Later, she was selected to take the lead in the fantasy film, Amazon High, alongside Karl Urban.
Blair starred as a present-day orphaned high school student who accidentally travels back in time to the mythical days of the Amazons.
For her ride on Wednesday, the star wore a pair of classic khaki jodhpurs with leather riding boots.
Making the look able to go from stable to street, Selma wore the riding pants with a pinstriped shirt.