|Date of birth||10 April 1983|
|Place of birth||Cardiff, Wales|
|Playing position(s)||Left-Back, Centre-Back|
|2003||Port Talbot Town||6||(0)|
|* Senior club appearances and goals counted for the domestic league only|
Giles began his career in the youth system at Cardiff City, the club he supported as a child. Alongside James Collins, he was offered a professional deal at the club and made his senior debut in March 2001 against Hull City as a substitute for Matt Brazier. He scored once for Cardiff against Rushden & Diamonds in the Football League Trophy before having brief spells at Barry Town and Port Talbot Town before joining Morecambe in November 2003. However, he did not play a first team match for the Shrimpers and left soon after. He then joined Carmarthen Town where he was a first team regular. In two seasons, he made over 70 appearances and scored 4 goals in the Welsh Premier League.
On 27 July 2006 he signed for Hereford United. He was a first team regular in the Bulls defence, and was named Fan's Player of the Month for September. However his season was effectively over by the end of October when he suffered two long-term injuries, initially suffering dizziness from a head injury. Once he had recovered he then sustained a back injury which ensured he did not play again in the 2006–07 season, and he was released at the end of the season.
On 26 June 2008 Giles joined Conference South team Newport County. Giles was a regular for Newport in the first half of the 2009–10 season but featured less in the second half of the season as Newport County were crowned Conference South champions with a record 103 points. However, Giles was released by Newport at the end of the season and agreed terms with Welsh Premier League side Llanelli three days later.
- "Giles Keen for Chance to Impress". South Wales Echo. 9 March 2002. Archived from the original on 3 March 2018. Retrieved 2 March 2018 – via HighBeam Research.
- Hayes, Dean (2006). The Who's Who of Cardiff City. Derby: Breedon Books. p. 73. ISBN 1-85983-462-0.
- "Cardiff 7-1 Rushden". BBC Sport. 16 October 2001. Retrieved 20 August 2012.
- "Turner brings in defender Giles". BBC Sport. 26 July 2006. Retrieved 14 August 2008.
- "Llanelli swoop for released Exiles' defender". welsh-premier.com. 30 April 2010. Archived from the original on 24 March 2012. Retrieved 30 April 2010.
- Martyn Giles at Soccerbase