The high schoolers waved flags, cheered, and danced during a special celebration at Immaculate Heart High School, a Catholic all-girls school in Hollywood.
Markle graduated from Immaculate Heart in 1999. Nearly two decades later, she is still remembered fondly by her former teachers, who are celebrating her alongside students who have never met her, ahead of her big day.
“I'm so happy for Meghan," student Lily Roth told Inside Edition. "She's always been such an activist for what we fight for here."
Some students wore fancy hats in honor of the royal wedding and offered their congratulations.
Theology teacher Christine Knudsen couldn't be more pleased with her former student.
"I’m really proud of the strong-willed woman she has become," she said. "This girl isn't just beautiful and smart — she's also got a lot of depth to her."
Markle was involved in theater, starring as Little Red Riding Hood in her sophomore year.
Her former drama teacher, Gigi Perreau, remembered that her former student "sparkled."
Perreau directed Markle in seven plays and says she was an all-around great kid.
“You see someone nice to the other kids, who gets good grades, doesn’t say anything bad about anybody,” she said when asked what she remembers about Markle.