Holly Parkinson-Hasler (born February 10, 1979) is a former professional tennis player from the United States.

[1] A right-handed player, Parkinson won six ITF circuit singles titles between 1997 and 1999, then began competing in the main draw of WTA Tour events.

After beating Kristina Brandi in the first round, she received a walkover against Chanda Rubin, before being eliminated by third seed Conchita Martínez.

After falling in the final round of qualifying at the 2000 Australian Open, Parkinson received direct entry into the main draw of the other three grand slam tournaments that year courtesy of her ranking, which peaked at 85 in the world in November.

[3] Her only win in a grand slam main draw came at the 2001 Australian Open where she defeated Spain's Ángeles Montolio, then lost a three-set match to local wildcard Evie Dominikovic.