Agathe Ursula Backer Grøndahl (1 December 1847 – 4 June 1907) was a Norwegian pianist and composer. She married the conductor and singing teacher Olaus Andreas Grøndahl in 1875, and was generally known thereafter as Agathe Backer Grøndahl. Her son Fridtjof Backer-Grøndahl (1885–1959) was also a pianist and composer, who promoted his mother's compositions in his concerts.