José Arnulfo Montiel Núñez (born 19 March 1988 in Asunción) is a Paraguayan footballer who plays as a midfielder for 12 de Octubre.
Montiel was a key part of the Paraguay national under-15 football team that won the 2004 South American Under-15 Championship.
In the 2008–2009 season, he was loaned to the Romanian Liga I team Politenica Iaşi, helping them to avoid relegation.
For the 2009–2010 season, Montiel was loaned to the Argentine club Tigre, making his debut on the 2nd day of Apertura 2009 tournament.
Montiel returned to Olimpia for the 2014 Clausura where he played 14 games before moving to the Copa Libertadores finalist Nacional Asunción in 2015.