The Reluctant Debutante is a vintage example of the sort of elegant, witty "polite" comedy that Hollywood used to pull off so well. Real-life husband and wife Rex Harrison and Kay Kendall are cast as newly wed Jimmy and Sheila Broadbent, two of London's more attractive aristocrats. Jimmy has a daughter, Jane (Sandra Dee), from a previous marriage; though the girl is dead set against it, Jimmy insists that Jane make her society debut in London. Daddy wants his darling daughter to meet the "right" kind of husband, but she's more interested in handsome-but-shady American musician David Parkson (John Saxon). Little does anyone know that David, secretly a titled millionaire, is actually the prize catch of the season. The matchless Kay Kendall manages to walk away with the picture, though she's given a run for her money by fifth-billed Angela Lansbury. The Reluctant Debutante was based on the play by William Douglas Home.
~ Hal Erickson, All Movie Guide