Hormilleja is a village and municipality in the province and autonomous community of La Rioja, in northern Spain. It lies within the Ebro Valley region of La Rioja, a predominantly agricultural area of north-central Spain.
The municipality covers an area of 7.44 square kilometres (2.87 square miles). As of 2011, it had a population of 175 people, making it one of the many small rural settlements that characterise this part of La Rioja.