- Born 2 December 1834 Lisrenny House, Co Louth
- Died 14 April 1916 Lisrenny House Co Louth
- Educated Rugby School, Warwickshire; Cheltenham College, Gloucestershire
- Occupation Captain in Louth Rifles
- Debut 6 August 1856 v United All England XI at Phoenix CC
- Cap Number 18
- Style Hand unknown
- Teams Co Louth, NICC
William Filgate was a member of a long established Co Louth landed family, who claimed descent from the Cromwellian settlement. He was the eldest of six cricket playing brothers and the second of seven children of William Filgate and Sophia Juliana de Salis, she was the daughter of the Fourth Comte de Salis, a landowner in both Ireland and England but a Comte of the by then defunct Holy Roman Empire. William married Georgina Harriet French in 1870, they had two daughters.
The Filgate brothers founded the Co Louth Club and kept it going for many years. William's younger brothers Leopold and Charles also played for Ireland. Charles, the youngest brother of the sextet was by far the best cricketer in the family playing with some success for both MCC and Gloucestershire.
William's one match for Ireland came in August 1856 against the United All England XI which had been founded four years previously by John Wisden and his friend Jemmy Dean, in protest against the financial arrangements in the All England XI which saw its founder and organiser, the legendary William Clarke, keep what they regarded as more than his fair share of the profits.
Ireland had agreed to field a XVI against the professionals but some confusion over selection resulted in eighteen players turning out for the hosts. It was quite a strong side and, thanks to fine bowling by Charles Lawrence and Joseph McCormick ended up winning by 6 runs. William's contribution to so famous a victory was, to say the least, minimal. Run out for 0 in the first innings, he completed his pair by being bowled by Wisden without scoring in the second. The Almanac's founder, incidentally, batted very well in the match, his first innings 29 being regarded as the best innings ever seen in Ireland.
William de Salis Filgate did not play for Ireland again, perhaps not only his poor performance but also his civic duties prevented him from doing so. Besides his work as a militia officer, he was a JP, Deputy Lieutenant of Louth and, in 1879, High Sherriff of the County. However he also found time to be a Master of Foxhounds for over 50 years from 1860. Lisrenny House survived the Troubles of the early 1920s, as did William's younger daughter Eileen, who died there in 1971.