Jirina Valenta (born Jirina Borilova; October 31, 1940) is a retired Czechoslovak-American wildwater and slalom canoeist who competed from the early 1960s to the early 1970s with then-husband Josef Šedivec under the last name Šedivcová.
She won two silver medals at the 1965 ICF Canoe Slalom World Championships in Spittal, earning them in the C2 Mixed and C2 Mixed Team events.
She also won a silver medal in the individual C2 Mixed Whitewater Downriver (Classic Race) event and a gold medal in the C2 Mixed Team Whitewater Downriver (Classic Race) event at the 1965 ICF Wildwater Canoeing World Championships, likewise held in Spittal.
Jirina's career began in then Czechoslovakia and ended in the United States.
She is credited with being the first woman to steer a whitewater canoe in slalom competitions as part of a two-person, mixed-gender team.
Until that time, conventional wisdom held that women, by nature of their gender, were probably incapable of directing a boat through a course of gates set up over river rapids.