1. Klaas-Jan Huntelaar was named Dutch Football Talent of the Year and Ajax "Player of the Year" in 2006, and was a part of the Dutch side that won the 2006 UEFA U-21 Championship where he became the tournament's leading goalscorer and received the player of the tournament award.
Klaas-Jan Huntelaar made his senior debut for De Graafschap on 8 February 2003, coming on as a substitute for Hans van de Haar against Roosendaal.
In January 2006, Klaas-Jan Huntelaar signed for Ajax, the club he had supported as a child.
Klaas-Jan Huntelaar made his Ajax debut after the winter break and scored his first goal for the team on 5 February 2006 against former club Heerenveen in a KNVB Cup tie.
In July 2006, Klaas-Jan Huntelaar became the first player to score at Arsenal's new Emirates Stadium in a testimonial match for Dennis Bergkamp.
Klaas-Jan Huntelaar scored nine goals in 15 appearances in all competitions before suffering torn ankle ligaments on 9 November 2008 in a league match against Sparta Rotterdam.
Klaas-Jan Huntelaar said in February 2012 that he would reach his playing peak in two years time, because of his later physical development.
On 23 December 2012, Schalke announced that Klaas-Jan Huntelaar signed a two-year contract extension to 30 June 2015.
On 31 January 2015, Klaas-Jan Huntelaar received a straight red card for a slide tackle on Manuel Schmiedebach of Hannover 96.
Klaas-Jan Huntelaar had not scored a league goal since November 2014, after going over 1,000 minutes and 13 games without scoring.
Klaas-Jan Huntelaar played in the 2001 FIFA World Youth Championship for the Netherlands under coach Louis van Gaal.
Klaas-Jan Huntelaar was included in the preliminary squad for the 2010 World Cup in South Africa.
Klaas-Jan Huntelaar followed this up with both goals for the Netherlands as they defeated Finland on 7 September 2010 in Rotterdam.
Klaas-Jan Huntelaar was the top goalscorer in the UEFA Euro 2012 qualifying competition with 12 goals, leaving him one shy of Northern Ireland's David Healy's all-time qualification record.
Since 2000, Klaas-Jan Huntelaar has been in a relationship with his girlfriend Maddy Schoolderman.