Carlos Arecio Amarilla Demarqui (born 26 October 1970) is a football referee from Paraguay.

He was the referee in the first qualifying match for the 2010 World Cup between Colombia and Brazil (14 October 2007).

[1] Amarilla was chosen to officiate at the finals, but withdrew following the failure of a fitness test by his assistant referees.

On 11 September 2012, he officiated a 2014 FIFA World Cup qualifying match between Uruguay and Ecuador.

On 15 May 2013, he also officiated Copa Libertadores 2013's Round of 16 match between Corinthians and Boca Juniors (1-1).