|Full name||Stanislaus Henricus Christina Valckx|
|Date of birth||20 October 1963|
|Place of birth||Arcen, Netherlands|
|Height||1.81 m (5 ft 11 1⁄2 in)|
|Playing position||Centre back|
|* Senior club appearances and goals counted for the domestic league only
After starting professionally with VVV-Venlo (second division), Valckx moved in 1988 to Eredivisie club PSV Eindhoven, being instrumental in the conquest of three leagues and two Dutch Cups – in the 1991–92 season, he scored four goals in 28 matches as the team renewed their domestic supremacy.
In 1992, Valckx, aged 28, moved abroad, to Sporting Clube de Portugal, helping the Lisbon side to the Portuguese Cup three years later, although he did not play in the final against C.S. Marítimo as in October 1994 he had already returned to his country and PSV, where he won one more league and another domestic cup before retiring in June 2000 at nearly 37 years of age, with more than 500 official appearances to his credit.
Subsequently, Valckx began working as a technical director at PSV, a post he occupied for several years. In 2008, he got into a conflict with general manager Jan Reker about the influence and role of player agent Vlado Lemić at the club; the following year, in the same capacity, he joined China's Shanghai Shenhua FC.
Valckx earned 20 caps for the Netherlands, and was picked for the squad which appeared at the 1994 FIFA World Cup. He contributed with four games, in a quarter-final elimination at the hands of eventual champions Brazil.
- Eredivisie: 1988–89, 1990–91, 1991–92, 1996–97, 1999–00
- KNVB Cup: 1988–89, 1989–90, 1995–96
- Johan Cruijff Schaal: 1996, 1997, 1998
- UEFA Super Cup: Runner-up 1988
- Intercontinental Cup: Runner-up 1988
- Valckx op punt van vertrek bij PSV (Point of no return for Valckx at PSV); Algemeen Dagblad, 25 April 2008 (in Dutch)
- Lemic, PSV’s intrigant of spindoctor? (Lemic, PSV’s schemer or spin doctor?); De Volkskrant, 26 April 2008 (in Dutch)
- Stan Valckx naar China (Stan Valckx to China); NU.nl, 3 January 2009 (in Dutch)
- Stanislaus Valckx dyrektorem sportowym Wisły (Stanislaus Valckx sporting director of Wisla); Wisla Kraków, 27 August 2010 (in Polish)
- Valckx keert als adviseur terug op het oude nest (Valckx returns to the old nest as a consultant); Voetbal International, 4 June 2014 (in Dutch)