Watch Mr. Wizard is an American children's television series that demonstrates the science behind ordinary things. The series' creator and on-air host was Don Herbert. Author Marcel LaFollette says of the program, "It enjoyed consistent praise, awards, and high ratings throughout its history. At its peak, Watch Mr. Wizard drew audiences in the millions, but its impact was far wider. By 1956, it had prompted the establishment of more than five thousand Mr. Wizard science clubs, with an estimated hip greater than one hundred thousand."

It was briefly revived in 1971, and a third version of the show ran during the 1980s on the children's cable television network Nickelodeon as Mr. Wizard's World.