The former Ghost Whisperer actress will make her Lifetime debut on the new show, which is based on the 2010 TV movie, on Sunday (April 8).
In a recent interview, she revealed that while her role as a sex worker at a massage parlor is just an acting job for her, it is a reality for other women.
"There really are economically [depleted] families that are put in these positions," Hewitt told The Deadbolt.
"There are women out there who are in sex worker positions that you would run into at the grocery store with their hair piled on top of their head and you have no idea," she continued. "But it's a reality."
Hewitt recently admitted that she has a crush on The Voice coach Adam Levine, but later apologised for making the crush public.
The Client List premieres tonight at 10pm on Lifetime.