Simon John Halliday (born 13 July 1960 in Haverfordwest, Pembrokeshire, Wales) is a former English rugby union international.
This was when he scored 113 not out against Kent in 1982, with a bowling lineup consisting of English Test cricketers Graham Dilley and Bob Woolmer.
His sporting career was interrupted by a serious leg injury when playing for Somerset against Middlesex in the Rugby Union County Championship in 1983.
England's selectors nevertheless attempted to fit Halliday into the side by playing him on the wing with Carling and Guscott at centre, but in the 1990 Five Nations campaign this move met with only mixed success in two matches - the victory over Wales followed by a defeat in the Grand Slam decider, against Scotland.
The move was regarded as enough of a success for Halliday to be retained on the wing as first choice for the next year, in the England side which won the 1992 Five Nations Championship with a Grand Slam.