When the Circus Came to Town chronicles the life of Mary Flynn (Montgomery), a woman nearing middle age living in a small town. When the circus comes through town, she realizes nothing will ever change unless she does something different, so she leaves her boring sheltered life to run away and join the circus. While adapting to her new life, she finds herself challenged, and in the end, happy with her new life.
| Actor | Role |
|---|---|
 Elizabeth MontgomeryMary Flynn | Mary Flynn |
 Christopher PlummerDuke Royal | Duke Royal |
 Eileen BrennanJessy | Jessy |
 Gretchen WylerOlivia Probashka | Olivia Probashka |
| AAnne ShropshireAunt Helen | Aunt Helen |
| TTommy MaddenLouie | Louie |
| TTimothy HillSchuller | Schuller |
| RRussell SaundersIvan Probashka | Ivan Probashka |
| MMark YerkesSergei Probashka | Sergei Probashka |
 Bob YerkesGeorgi Probashka | Georgi Probashka |
 J. Don FergusonAndre Probashka | Andre Probashka |
 Anne HaneyBlossom | Blossom |
| GGeorge EllisRodriguez | Rodriguez |
| WWallace WilkinsonMinister | Minister |
| CClara DunnMs. Bailey | Ms. Bailey |
| TTena WorthingtonMrs. Sharp | Mrs. Sharp |
| WWilliam StarrsMr. Salveson | Mr. Salveson |
| BBobbi KempSexy Girl | Sexy Girl |
| CCarol StebbingPriscilla | Priscilla |
| CCharles KaufmanMan in Diner | Man in Diner |
| DDon DevendorfMotel Clerk (uncredited) | Motel Clerk (uncredited) |
 Charles LawlorRedneck (uncredited) | Redneck (uncredited) |
| NNicholas WarfJuggler (uncredited) | Juggler (uncredited) |