|Full name||Stephan Keller|
|Date of birth||31 May 1979|
|Place of birth||Zürich, Switzerland|
|Height||1.90 m (6 ft 3 in)|
|Playing position||Centre Back|
|until 1999||Grasshopper Club Zürich|
|2004||→ Aarau (loan)||12||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 12 February 2011.
‡ National team caps and goals correct as of 29 December 2009
Keller is a defender, born in Zürich, who played 13 years youth career for Grasshopper Club Zürich. He made his debut in professional football, being part of the Neuchâtel Xamax squad in the 1999–2000 season.
Keller spent the majority of his career playing for various clubs in the Swiss Super League before moving to Germany to play for then, 2. Fußball-Bundesliga team, Rot-Weiß Erfurt. After spending half a season there he moved to the Netherlands where he spent four years playing in the Dutch Eredivisie playing for RKC Waalwijk and De Graafschap respectively.
After four years in the Netherlands, Keller moved to Australia to play for Sydney FC in the A-League. On 26 July, he made his debut for Sydney FC in a friendly match against Newcastle Jets. He re-signed with Sydney FC for the 2010–11 A-League season. He scored his first goal for Sydney FC in the Round 5, 3–1 loss to Adelaide United at the Sydney Football Stadium. Following a poor second season and Champions League campaign from Sydney FC, Keller was released along with several other players.
Keller returned to Europe and sparked interest from former Eredivise club RKC Waalwijk. However, in a shock move Willem II signed Keller on a two-year contract, snatching him from under the nose of his former employee.
After being dropped to the reserves during the back half of the 2011–12 season, Keller and Willem II mutually terminated his contract with the club after he was told he was surplus to requirements, following the clubs promotion to the Eredivise for the 2012–13 Eredivisie season.
With Sydney FC:
- Birrer, Peter M. (1 March 2011). "Abenteurer und Geniesser in Australien" (in German). Tages-Anzeiger. Retrieved 6 August 2012.
- Gardner, James (27 July 2009). "Early signs are good for Sydney as Jets struggle to find answer to their problems". smh.com.au. Retrieved 6 August 2012.
- Hassett, Sebastian (26 November 2009). "Keen Keller commits to more time in Sydney". Sydney Morning Herald. Retrieved 17 March 2010.
- "Sergio Inflicts More Sydney Misery". FourFourTwo Australia. 4 September 2010. Retrieved 4 September 2010.
- "Sydney FC player clean out". SBS – The World Game. 14 May 2011. Retrieved 14 May 2011.
- "RKC Waalwijk wil transfervrije Keller terughalen" (in Dutch). voetbal international. 2 July 2011. Retrieved 3 July 2011.
- Door, Yorick Hokke (2 July 2011). "Keller staat voor terugkeer naar RKC" (in Dutch). Goal.com. Retrieved 3 July 2011.
- Robin, Robin (7 July 2011). "Willem II vindt in persoon Keller ervaren speler voor verdediging" (in Dutch). soccernews.nl. Retrieved 8 July 2011.
- de Bekker, Peter (8 August 2012). "Stephan Keller verbreekt contract Willem II" (in Dutch). omroepbrabant.nl. Retrieved 27 August 2012.