Sierra High School is part of the Valley Oak League, of the CIF Sac-Joaquin Section.

It has 12 athletic teams - track, cross country, wrestling, soccer, basketball, football, baseball, softball, swimming, golf, water polo, and tennis.

They have won 20 Sac-Joaquin Section Championships, 3 in cross country, 8 in track, 4 in women's soccer, 3 in softball, 1 in boys basketball, and 1 in football.

This year also marked the first Sac-Joaquin Section title for the boys basketball team.

In the fall of 2015, the football team won its first Sac-Joaquin Section football title and followed that with a CIF State division IVA title by beating Chowchilla HS 20–15 on a score with 54 seconds left in the game.