A siesta is a short nap taken in the early afternoon, often after the midday meal. Such a period of sleep is a common tradition in some countries, particularly those where the weather is warm.

SIESTA (Spanish Initiative for Electronic Simulations with Thousands of Atoms) is an original method and a software implementation for performing electronic structure calculations and ab initio molecular dynamics simulations of molecules and solids.

SiESTA! is a music festival in Hässleholm, Sweden. It was arranged for the first time in 2003 by the non-profit organization KF Markan. The festival takes place in the outskirts of Hässleholm during three days in the first weekend of June between Thursday and Saturday. Since the first festival in 2003, its attendance has increased from 1,500 visitors to approximately 10,500 people in 2011. The audience is mainly from Sweden, Norway and Denmark. The cornerstones of the festival is faith, hope and love.