Ernest Sydney "Syd" King (1 August 1873 – 14 February 1933) was an English footballer and manager, and one of the most important figures in the early history of West Ham United.

Born Chatham, Kent and educated at Watford Grammar School for Boys, he started his career as a full back with Northfleet and had been club captain.

[4] In 1900 he was retained as a member of the squad after the club's transition to West Ham United, and continued to play for them until 1903, recording 59 league and 7 FA Cup appearances in total.

[4] The boss at West Ham was Syd King, an outsize, larger-than-life character with close-cropped grey hair and a flowing moustache.

On the eve of the 1904–05 season a small postcard of the team photograph was issued and featured the following text from King on its reverse endorsing Oxo: His tenure at West Ham included their election to the Football League in 1919, which coincided with a personal cheque from the board for £1,500[5] that paid tribute to his twenty years of service for the club.

Part of the reason that this consistency was possible, was due to Syd King signing players that went on to become West Ham legends and record holders, as well as England internationals, including Jimmy Ruffell, Ted Hufton and Vic Watson.

Syd King was appointed a shareholder of West Ham United in 1931, but the team was relegated in the 1931–32 season back to Division Two.