Robert John Holthaus (December 28, 1928 – August 2, 1985), better known as Bob Holt, was an American actor, best known for his voice work.

Holt's first film role came in 1950, acting as Octavius Caesar in Julius Caesar. His career as a voice artist began with the 1968 short film Johnny Learns His Manners, for which he provided all of the voices. He later appeared in such works as Bedknobs and Broomsticks, several animated television specials with Dr. Seuss, for example, The Lorax (1972), Dr. Seuss on the Loose (1973), The Hoober-Bloob Highway (1975) and The Grinch Grinches the Cat in the Hat (1982) and the animated film version of Charlotte's Web as Homer Zuckerman.