Ricky Foster made his senior debut for Aberdeen aged 17 on 10 May 2003 in a Scottish Premier League match against Partick Thistle. Foster became a first team regular under Jimmy Calderwood and signed a two-year contract extension on 31 July 2007.
On 31 August 2010, Foster moved on a season-long loan to SPL champions Rangers, with Gers striker Andrius Velička moving in the opposite direction. Foster made his first Rangers start on 20 October in a Champions League group stage match against Valencia at Ibrox, where he was selected as man of the match.
On 6 January 2012 he signed for Championship side Bristol City on a two and a half-year contract for an undisclosed fee. Foster signed for Rangers on a two-year contract in June 2013. Has represented Scotland at both Under 21, and Full level.The experienced defender signed for Ross County on 30th June 2015, in a two-year deal.