Mamma Mia! The Party confirms new London casting

Jon Osbaldeston will join the London cast of Mamma Mia! The Party as Nikos from 28 January 2026.

He replaces Fed Zanni and joins the existing company at the immersive theatrical dining experience, which is currently booking until April 2027.

Osbaldeston’s theatre credits include Les Miserables, Fiddler on the Roof, Kiss of the Spiderwoman and Leonardo in the West End. He is also a co-founder of musical theatre group The WestEnders.

He joins cast members Marianne Benedict and Kimberly Powell, who share the role of Kate at certain performances, alongside Oscar Balmaseda as Host and Fernando, Paola Fareri as Konstantina, Natalie Winsor as Debbie, AJ Bentley as Adam, Dawn Spence as Grandma, Rebecca Stenhouse as Nina, Allie Ho Chee and Rosie Rowlands as Bella, Constantine Andronikou as Robin and swing, Robban Hogstrom as Leo and swing, Nathan Shaw as Carlos and swing, Kelly Aaron as Sue and swing, Claudia Bradley as Loretta and swing, and Deschenes Graham as Joyce and swing. The production’s musicians include John Donovan, Flo Blue, Luke Higgins, Luke Roberts and Steve Rushton.

Since opening in August 2019, Mamma Mia! The Party has welcomed more than 600,000 guests and played over 1,500 performances, attracting audiences from 110 countries. The experience places audiences inside a taverna on the Greek island of Skopelos, where a story unfolds alongside a four-course Greek meal, followed by a post-show disco featuring songs by ABBA.

The production is executive produced by Björn Ulvaeus and Pophouse Entertainment. The London version is co-directed and choreographed by Stacey Haynes and Roine Söderlundh, with a book by Sandi Toksvig, music and lyrics by Benny Andersson and Björn Ulvaeus, and design work by Bengt Fröderberg, Patrick Woodroffe, Gareth Owen and Annsofi Nyberg. Casting is by David Grindrod for Grindrod Burton Casting.