John Cameron Semple (born 1947) is a botanist, cytotaxonomist, professor emeritus, and adjunct professor at the University of Waterloo in Ontario, Canada. He was born in Boston and earned a degree of Bachelor of Science in 1969 from Tufts University, followed in 1971 and 1972 by Master of Arts and Doctor of Philosophy degrees from Washington University in St. Louis. Semple is known for his work with members of the tribe Astereae, particularly goldenrods, American asters, and goldenasters, and he maintains the University of Waterloo Astereae Lab website. Semple's wife is Brenda, and in 2013, he named a newly-discovered goldenrod species Solidago brendiae in honor of her.