Among the list is actress Julia Roberts, who Markle says was the first person who motivated her to begin her own acting career.
"She was the first person I saw on screen and thought, 'That looks like so much fun; I wanna do that,'" the actress wrote. "When I was younger, someone once told me, 'You kind of look like Julia Roberts in profile.' It was the best compliment of all time."
Novelist Toni Morrison is also credited with impacting Markle's life. "In college, I took a class on the works of Toni Morrison," the philanthropist shared. "The first time I read The Bluest Eye, I thought, 'Wow! She creates this world for you that you get to feel a part of.'"
Also on the list is singer Joni Mitchell, Rosie the Riveter, entrepreneur Suhani Jalota, primatologist Dian Fossey, NBCUniversal Chairman Bonnie Hammer, Former U.S. Secretary of State Madeleine Albright, chef and food activist Alice Waters and -- most importantly -- Markle's mother, Doria Radlan.
"My mom's a yoga instructor, but she does social work, as well, and she works specifically with the geriatric community," the actress states. "For me to watch this level of life-long sensitivity to nurturing and caregiving, but at the same time my mom has always been a free spirit. She's got dread locks and a nose ring. She just ran the L.A. Marathon. We can just have so much fun together, and yet, I'll still find so much solace in her support. That duality coexists the same way it would in a best friend."