Fitness may refer to:
Physical fitness, a state of health and well-being of the body Fitness culture, a sociocultural phenomenon surrounding exercise and physical fitness Fitness (biology), an individual's ability to propagate its genes Fitness (cereal), a brand of breakfast cereals and granola bars Fitness (magazine), a women's magazine, focusing on health and exercise Fitness (Apple), a mobile application developed by Apple Fitness and figure competition, a form of physique training, related to bodybuilding Fitness approximation, a method of function optimization in evolutionary computation or artificial evolution methodologies Fitness function, a particular type of objective function in mathematics and computer science "Fitness", a 2018 song by Lizzo
See also FitNesse, a web server, a wiki, and a software testing tool Survival of the fittest