Co Westerik or Jacobus Westerik was a Dutch artist who was born in 1924 in The Hague and died in 2018.

Westerik made paintings, watercolors, drawings, lithographs and etchings. He worked daily, half of the year in his studio in Rotterdam and the summer months in southern France. He received the Jacob Maris Prize three times, in 1951 and '55 for painting and in 1953 for drawing and in addition the Rembrandt Prize of the city of Leiden, the State Prize for Visual Arts and Architecture, the Cultural Prize of South Holland, the Hendrik Chabot Prize of the Carnation Fund Rotterdam and the Jeanne Oosting Prize in 1979.