Joop "January" Tjaarda van Sterkenburg, later known as John Tjaarda, was a product and automotive designer in the United States.
He was born in Sterkenburg, The Netherlands, in 1897 and trained in aeronautical design in the United Kingdom, later serving as a pilot in the Dutch Air Force.
After emigrating to the United States in 1923, he changed his name to John Tjaarda and worked in custom coachbuilding in Hollywood. During the 1920s, he worked on a series of streamlined monocoque designs, known as the "Sterkenburg series", before joining the Briggs Manufacturing Company as chief of body design. There he developed a concept car for the Ford Motor Company to be shown at the Century of Progress Exhibition (1933-1934) in Chicago.
Known as the "Briggs Dream Carolina", this was a streamlined rear-engined design, based on his previous work.
Re-engineered as a front-engined car, this design was developed into the 1936 Lincoln-Zephyr. Tjaarda also designed an exhibition "Kitchen of Tomorrow" for Briggs in 1934.
Tjaarda"s son, Tom Tjaarda also became an automotive designer, working mainly in Italy.