The sport famously known for its "Grand Slam" is tennis. Achieving a Grand Slam in tennis means winning all four of the major championships in a single calendar year: the Australian Open, French Open, Wimbledon, and US Open. This feat is incredibly challenging and showcases a player's consistency and excellence across different surfaces and conditions. Iconic players like Roger Federer, Rafael Nadal, and Serena Williams have captivated audiences by successfully achieving or competing for Grand Slam titles throughout their careers.