Despite being one of the most famous archaeological cemeteries in Peru, many questions remain about the people who were buried at the Paracas Necropolis of Wari Kayan, which was first excavated by Julio C. Tello in 1925. Here, we use bioarchaeology and biogeochemistry to elucidate the lives of individuals buried at Wari Kayan. More specifically, we present 90 new δ13Ckeratin and δ15Nkeratin values from 14 individuals buried at Wari Kayan and two artifacts made of human hair (mean δ13Ckeratin (VPDB)=-15.3±0.9‰ (1σ, n=90) and mean δ15Nkeratin (AIR)=+15.5±1.2‰ (1σ, n=90)). We interpret these light stable isotope data from archaeological human hair samples from the Paracas Necropolis of Wari Kayan as evidence for a mixed diet of C4 and C3 foods as dietary carbon sources and marine products as dietary nitrogen sources. Sequential hair samples from the same individuals do not exhibit large isotopic differences in hair that formed at different times before death. In addition to elucidating paleodiet at this important site, we interpret sequential isotopic hair data as evidence of a population whose diet was predominately coastal in the last weeks or months of life, either remaining on the coast or consuming coastal products in the highlands. These data elucidate paleodiet as well as the utility of applying newer isotopic methods to archaeological human remains from older museum collections to gain a better understanding of the past.