Strikeforce (or Strikeforce Fighting Championship) is an American professional kickboxing and mixed martial arts promotion based in San Jose, California.

On March 10, 2006, Strikeforce held Strikeforce: Shamrock vs. Gracie, the first MMA event sanctioned by the state of California, taking place at the HP Pavilion in San Jose, California. With 18,265 in attendance, Shamrock vs. Gracie broke the previous record for the largest audience at a North American MMA event, earlier held by UFC 57. The record was since broken by UFC 68 and K-1 HERO'S Dynamite!! USA, although Shamrock vs. Gracie retains the paid attendance record of 17,465.^[1]

Among the promotion's roster are former UFC champion Frank Shamrock, WWE Tough Enough winner and AKA fighter Daniel Puder, and San Shou champion Cung Le. Recently the promotion contracted Renato Sobral following his termination with the UFC stemming from his violation of UFC regulations. [1]

Strikeforce is promoted by American K-1 promoter Scott Coker and Silicon Valley Sports and Entertainment, operators of the HP Pavilion and the San Jose Sharks NHL hockey club.