Connors won eight Grand Slam singles titles (five US Opens, two Wimbledons and one Australian Open) and two Grand Slam doubles titles (at the US Open and Wimbledon), and was a runner-up in seven Grand Slam singles finals, one Grand Slam doubles final and one Grand Slam mixed doubles final. He held the top ranking for a then-record 160 consecutive weeks from July 29, 1974 to August 22, 1977 and an additional eight times during his career for a total of 268 weeks. He was the first male player to rank No. 1 for more than five years in total. He held a year-end top ten ranking for a record 16 years.
Connors won 110 ATP-listed singles titles, more than any other male player in the open era. He won three year-end championships and 17 Championship Series titles, predecessors of the Masters 1000 series. In 1974 he became the second man in the open era to win at least three of the four Grand Slams in a calendar year, and is presently one of six men to achieve the feat. He is also the only person to win US Open singles championships on grass, clay, and hard courts. His career win-loss record of 1249–277 (81.85%) is second after Björn Borg (82.7%). He reached more Grand Slam quarter-finals (41) than any other male player. He is often ranked among the greatest tennis players of all time.
Connors has worked as a tennis commentator for NBC-TV, BBC and Tennis Channel. He was the coach of Andy Roddick from 2006 to 2008. In 2013 he was announced as the new coach of Maria Sharapova but the partnership lasted for just one match. He was engaged to fellow tennis player Chris Evert from 1974 to 1975, and since 1979 he has been married to former Playboy model Patti McGuire, with whom he has two children.