Hartmut Esslinger is a German-American industrial designer and inventor. He is best known for founding the design consultancy frog, and his work for Apple Computer in the early 1980s.

frog is a global creative and design consultancy founded in 1969 by industrial designer Hartmut Esslinger in Mutlangen, Germany, where it was initially named “esslinger design”. Soon after the company moved to Altensteig, Germany, and then opened a new studio in Palo Alto, California, and ultimately to its current headquarters in San Francisco, California. The company has studios in North and Central America, Europe, and Asia.