He was selected as a referee for the 2010 FIFA World Cup. Lannoy refereed the group stage match between The Netherlands and Denmark and the match between Brazil and Ivory Coast. He was also picked as one of the referees for Euro 2012. On 28 June 2012, Lannoy refereed the Euro 2012 semifinal between Italy and Germany, won 2-1 by Italy. He booked Mario Balotelli, in accordance with UEFA guidelines, for taking his shirt off after a goal celebration.