Roger Federer is a Swiss professional tennis player. He was ranked world No. 1 by the Association of Tennis Professionals (ATP) for 310 weeks, including a record 237 consecutive weeks, and has finished as the year-end No. 1 five times. He has won 103 ATP singles titles, the second most of all time, including 20 Grand Slam singles titles, a record eight men's singles Wimbledon titles, an Open Era record-tying five men's singles US Open titles, and a record six year-end championships.