Original cast member Phil Nichol returns to the show, reprising his role of Hugo/Loco Chanelle.
Melissa Jacques will step up into the role of Margaret New having understudied the part for the past year.
She takes over from Rebecca McKinnis who is leaving to play Heidi Hansen in Dear Evan Hansen.
Also joining the cast are Alexander Archer as Mickey, Tilly La Belle Yengo as Fatimah and Gillian Ford as the understudy for Margaret, Miss Hedge and Ray.
All play their first performances from 30th September 2019.
Nica Burns, Producer of Everybody’s Talking About Jamie said: “Sad as we are to lose Rebecca Mckinnis, we are delighted that she is leaving to play the role of Heidi Hansen for the UK premiere of the Broadway hit, Dear Evan Hansen.
"Rebecca started with Jamie as understudy 2 years ago and was promoted into the leading role of Margaret New and made it her own. It is wonderful to see Melissa Jacques following in her footsteps as she too steps up to the role of Margaret.
"Like Rebecca, Melissa is a terrific actress with a fantastic voice. There is an extraordinary wealth of performing talent in the UK and it is exciting to see artists developing within a company and establishing themselves as lead performers.
"A big welcome back to comedian and actor Phil Nichol who so brilliantly originated the role of Loco Chanelle at the Apollo.”
Inspired by a true story, Everybody’s Talking About Jamie has proved a hit on the West End ever since opening in 2017.
Supported by his brilliant loving mum and surrounded by his friends, 16-year-old Jamie overcomes prejudice, beats the bullies and steps out of the darkness, into the spotlight.