The Saturday Night Fever superstar wrote to Theatre South Productions to give his blessing to their performance of Disco Inferno.
And cast members said the note has given them a "thrill" ahead of the opening night of the show.
Leading man Kevin McGuire, 33, said: "The show is coming together really well but receiving a good luck message from John Travolta has given the cast an extra thrill.
"I wasn't sure if he would write back to us or not but I can't quite believe that he has. And, after getting Idina Menzel's name wrong at the Oscars, I'm flattered he managed to get my name right."
The theatre group is putting on a production of Disco Inferno at Eastwood Park Theatre next week.
Choreography for the show is inspired by Travolta's turn in seventies dance movie Saturday Night Fever.
Cast members thought they would write to the performer and let them know abut the show.
And they were left stunned when he wrote back. In his letter the Grease star said: "Dear Kevin, congratulations on your production of Disco Inferno at the Glasgow Theater! I know you will be most successful."
Receiving best wishes from Travolta is not the first the Theatre South have been given the thumbs-up from big names.
Sir Tim Rice wrote to the club in 2012, wishing them good luck from himself and Elton John for their production of Aida.
Fonz actor Henry Winkler gave the club a good luck message ahead of last year's production of Happy Days.
The group, based in Giffnock, is celebrating its 21st anniversary. It was launched by husband and wife Alastair and Jacqueline Runciman who said they were delighted the company still performs.
l Disco Inferno is on at Eastwood Park Theatre from Tuesday, March 25 to Saturday, March 29.