In tennis, the term Big Four refers to the quartet of men's singles players Roger Federer, Rafael Nadal, Novak Djokovic, and Andy Murray. They reigned as the four best players in the world every season from 2008-2012. These players were considered dominant in terms of ranking and tournament victories, including Grand Slam tournaments and ATP Masters 1000 events, as well as the ATP World Tour Finals and Olympic Games through 2013.

          Federer was the first to come to prominence after winning Wimbledon in 2003 and established himself as the world No. 1 by the beginning of 2004. Nadal followed in 2005 after a French Open triumph including a win over Federer, and they occupied the top two places in the ATP rankings for 211 consecutive weeks from July 2005 to August 2009. Djokovic, from 2007, and later Murray, from 2009, increasingly challenged Federer's and Nadal's dominance with seasonal consistency: Djokovic captured three of the four major tournaments in 2011, and in 2012 the quartet won one Major tournament apiece. In 2011 Nadal declared that his and Federer's period of joint dominance had ended, owing to the ascent of other players, notably Djokovic and Murray.