"Oh no, Mrs. Burke! I thought you were Dale!" is part of the dialogue featured in a 1968 through 1970 Post Grape-Nuts cereal television commercial advertising campaign in the United States. This phrase long endured in pop culture media, well after the commercial disappeared from the television screen. Variations of, and direct references to, this catchy dialogue continued to appear in other media as long as two decades after the ad campaign had expired.

In this commercial, a young man in a backyard swimming pool mistakes his girlfriend's mother for her daughter, and he exclaims, "Oh no, Mrs. Burke! I thought you were Dale!"

The 30 second commercial spot[1]that includes this line first aired on television across the U.S. on July 19, 1968. It ran in prime-time slots with a number of popular TV series. A 10 second spot, edited down from the full length ad, also ran during this period. Two print ads associated with this campaign appeared in issues of LIFE magazine.

The enduring place of this phrase in pop culture history is evidenced in the many spoofs, skits, and jokes spawned by the commercial, covering 2 decades and appearing in a wide range of comedy variety shows and movies, newspapers, magazines, and literature.

Five single-panel cartoon gags were syndicated: one in MAD and two in Playboy magazines. Comic-strip artist, Bil Keane, penned two panels. The first line of an Erma Bombeck book references it. Four or more television comedy/variety shows did skits and jokes about this ad in the early '70s, such as The Tonight Show with Johnny Carson, The Carol Burnett Show, and Rowan and Martin's Laugh-In. A sketch based on it appears in 1977's Kentucky Fried Movie, and over a dozen “riffs” on the commercial's dialogue feature in the long-running '80s and '90s television comedy series, Mystery Science Theater 3000.

The Benton & Bowles, Inc. ad campaign, which included a number of individual television commercials featuring "mother/daughter look-alikes", employed real people, rather than professional actors, to impress upon consumers the idea that a mother may remain as healthy and young-looking as her teenage daughter "with exercise...and Post Grape-Nuts for breakfast."

During this era, similar TV ad campaigns for other products also utilized the mother/daughter mistaken identity theme, such as for Ivory Soap.