Union Christian Academy (UCA) is a private Christian school serving students in prekindergarten through grade 12 in Fort Smith, Arkansas, United States. It was founded in 2005 as a result of a merger of the former Harvest Time Christian School, Fort Smith Christian School and River Valley Christian School. For the 2014-15 school year, Union Christian serves more than 200 students in prekindergarten through grade 4 at its elementary campus and nearly 300 students in grades 5 through 12 at its middle/high school campus.