The 34-year-old actress and singer said Wednesday that she will honor Rivera with a special performance Thursday on the ABC late-night show.
Riley's former Glee co-star Kevin McHale tweeted a message of support Wednesday.
"Our queen is singing for our other queen," he wrote. "Thankful for @MsAmberPRiley always. She's the strongest. Can't wait to watch."
Riley and Rivera played Mercedes Jones and Santana Lopez on Glee, which had a six-season run on Fox from 2009 to 2015.
Rivera died of an accidental drowning July 8 while boating with her 4-year-old son, Josey. The actress was 33 years old.
Riley remember Rivera as her "favorite duet partner" in a tribute July 13 on Instagram.
"I love you. I miss you. I don't have words right now, just lots of feelings. Rest In Peace Angel, and know that your family will never have to worry about anything," she wrote.
Riley remembered Rivera as a smart and funny friend in another post July 23.
"miss you baby girl and I love you," Riley wrote. "#NayaRivera I'm so mad the world will never see how high you could have soared. Her brain was brilliant. She was smart and quick as a whip. Always had me in stitches, we would be in tears laughing so hard at one another."
"There was never competition, or shade, or intimidation with us. Just pure adoration and mutual respect. You deserved better," she said. "You were so much more than just this show. Your talent outshined us all so many times!"
Heather Morris, who played Brittany Pierce on Glee, has also paid tribute to Rivera since the actress' death. Morris sent a message of support to Glee fans this month.
In addition to Glee, Riley is known for winning Dancing with the Stars Season 17 and starring in a West End production of Dreamgirls. She most recently appeared in the film Infamous, co-starring Bella Thorne and Jake Manley.