|Date of birth||31 October 1971|
|Place of birth||Edinburgh, Scotland|
|Height||6 ft 3 in (1.91 m)|
|2002||→ Ayr United (loan)||1||(0)|
|2002–2003||Heart of Midlothian||8||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 21:12, 2 October 2009 (UTC).
A forward, Twaddle began his career with junior club Dunbar United. He entered senior football when he signed for St Johnstone in 1994. He remained at McDiarmid Park for two years, making 51 league appearances and finding the net on ten occasions. In 1996, he joined Raith Rovers in an £80,000 deal. He made 32 appearances for Rovers in two years, scoring four goals.
He moved to Morton in 1998 for a fee of £150,000, but his stay at Cappielow was brief. Scottish Premier League club Motherwell signed him later that year, also for £150,000. Twaddle signed for Hearts, the club he supported as a boy, in June 2002. He only played eight league games for the Jambos in his twelve months with the Edinburgh side.
In 2003, he joined St Mirren, but again his stay was a short one, and he moved on after making only three appearances. Twaddle joined Scottish junior club Penicuik Athletic in the summer of 2004.
- Crooks, Lauren (30 September 2012). "Football star reveals how he hit rock bottom as he blew £1million on his gambling addiction". Sunday Mail. Trinity Mirror. Retrieved 30 September 2012.
- "Hearts seal Twaddle signing". BBC Sport. BBC. 13 June 2002. Retrieved 30 September 2012.
- "Haddington hoping to make hay with George". Edinburgh Evening News. Johnston Press. 8 January 2005. Retrieved 30 September 2012.
- "Kev has gear for marathon cup warm-up". Edinburgh Evening News. Johnston Press. 16 March 2006. Retrieved 30 September 2012.