Cung Lê was born in Saigon, South Vietnam (now Ho Chi Minh City, Vietnam). In 1975, three days before the Fall of Saigon, Cung Le and his mother Anne left Vietnam by helicopter under heavy gunfire. Le’s father stayed in Vietnam and was caught as a prisoner. After a few months in a refugee camp in the Philippines, Le ended up in San Jose, California, where early discrimination and bullying inspired him to learn martial arts. His mother enrolled him in Tae Kwon Do classes at the age of 10.

Le began wrestling competitively at age 14. After being inspired to box by Sylvester Stallone´s Rocky, Le graduated and earned All-American honors in wrestling his junior year at San Jose High School. He went on to wrestle for West Valley College in Saratoga, California, and won the California Junior College State Championship in the 158 lb weight class in 1990 also earning junior college All-American honors. Le also is practiced in a variety of martial arts such as Kuntao and Sambo. He began training in Sanshou (Sanda) and kickboxing around age of 19 because it complimented his Tae Kwon Do and wrestling background. Le held a professional kickboxing record of 17–0 and is a three-time world champion in kickboxing.

Le is undefeated in his Sanshou/kickboxing career (17–0). He has won three US Open International Martial Arts Championships (1994, 1995, 1996). In 1998 he won the Shidokan tournament championship. He has also won four US National Championships (Orlando, FL, 1994, Dallas, TX, 1995, Baltimore, MD, 1997). He earned three bronze medals in his amateur Sanshou world competition compiling an overall amateur record of 18–3. He has been a three-time captain of the United States teams that competed and was the U.S. team captain at the World Wushu Championships in 1997 (Italy) and 1999 (Hong Kong). On December 15, 2001 he defeated Shonie Carter by unanimous decision in San Jose, California, to win the IKF International Kickboxing Federation Pro Light Heavyweight Sanda World Title. In May 2003, Le entered into K-1 competitions where he garnered a 3–0 career record, including one knockout.

Le made his mixed martial arts debut at Strikeforce: Shamrock vs. Gracie on March 10, 2006, at the HP Pavilion at San Jose, knocking out kickboxing rival Mike Altman at 3:51 of the first round. Le first met Altman in San Jose, in 1999, in a kickboxing bout where he defeated Altman via a body shot in the third round. Three months later he faced KOTC veteran Brian Warren, knocking him out at 4:19 of the first round. Le had also faced Warren in a K-1 Sanshou bout where he won by decision. At Strikeforce: Triple Threat on December 8, 2006, Le defeated UFC veteran Jason Von Flue in 0:43 of round one, when the fight had to be stopped due to a cut from a kick. Le went on to fight Tony Fryklund. Le beat Fryklund via TKO due to strikes late in the third round. Soon after Le fought Sammy Morgan at Strikeforce: Four Men Enter, One Man Survives where he won the bout via TKO.

On March 29, 2008, Le defeated long time MMA veteran Frank Shamrock in a fight co-promoted by Strikeforce and EliteXC at the HP Pavilion in San Jose. Le won via TKO when Frank Shamrock’s right arm ( ulna) was broken after a series of kicks, making him the new Strikeforce Middleweight Champion. On September 17, 2009, Strikeforce CEO Scott Coker announced that Le had relinquished his belt after securing a major motion picture deal.

Twenty-one months after his last fight, Le returned to Strikeforce to face Scott Smith at Strikeforce: Evolution on December 19, 2009. Le suffered his first MMA defeat there, losing via TKO at 3:25 of the third round. After the match, Le expressed interest in an immediate rematch with Smith. His wish was granted on June 26, Strikeforce: Fedor vs. Werdum, in which Le defeated Smith via TKO in the second round to avenge his only MMA loss at the time.

Le co-starred in the live-action Tekken film, based upon the popular martial arts fighting game, as Marshall Law, released November 5, 2009 for the American film market. Le had supporting roles in the science fiction film Pandorum with Dennis Quaid and Ben Foster, and Fighting, released in 2009 alongside Channing Tatum. He also starred in a Hong Kong martial arts film Bodyguards and Assassins, which was released on December 18, 2009; his film was the first time he worked with and had a fight scene with Hong Kong martial arts superstar Donnie Yen.

Le has two sons with his ex-wife. He and his second ex-wife were married in August 2009. The couple had their first child together in 2010.

Le was briefly linked to a matchup with Vitor Belfort on November 19, 2011, at UFC 139. However, Belfort was removed from the bout and replaced by former Pride FC Middleweight Champion Wanderlei Silva. Le managed to confuse Silva with his unorthodox kicks, and landed a spinning backfist that dropped Silva. During the second round, Silva managed to shake Le with huge punches and knees that completely broke Le’s nose. Le was stunned, bloodied and fell to the ground, and the fight was stopped by the referee. Afterwards, in the press conference, Dana White commented that it was a good stoppage and that Cung was taken to the hospital.

Le has said that it is basically the UFC or bust for him at this point in his fighting career. “I know for a fact that if I do fight again, it’s going to be in the UFC. I’ve never fought in the UFC, but I would love to fight in the UFC. But right now because of my contract with Showtime and Strikeforce, hopefully things can work out because there is a show in San Jose that Cain Velasquez is the main event. I would love to fight in San Jose for the UFC ….” In an interview with BloodyElbow on October 27, 2012, Le revealed he originally signed a six-fight contract with the UFC.

Le was scheduled to face former UFC Middleweight Champion Rich Franklin on July 7, 2012, at UFC 148. However, due to an injury to headliner Vitor Belfort, Franklin instead faced Wanderlei Silva in a 190 lb catchweight rematch on June 23, 2012 at UFC 147. Le instead faced former title contender Patrick Côté. He earned his first UFC win via unanimous decision (30-27, 30-27, 30-27).

Le faced Rich Franklin in the main event on November 10, 2012, at UFC: Macao. Cung Le won the fight via KO with a powerful hook punch to Franklin’s head at 2:17 of the first round.

Le had a lead role in the 2012 action film Dragon Eyes, costarring Jean-Claude Van Damme and produced by Joel Silver. The movie is based on the Akira Kurosawa classic Yojimbo and is “MMA-themed”. Also in 2012, Le played Bronze Lion in The Man with the Iron Fists, a film directed by RZA.

In November 2013, it was announced that Le would serve as the chief coach and mentor on The Ultimate Fighter: China, the China-based version of The Ultimate Fighter which began airing in December 2013.

After over a year-and-a-half of being away from competition, Le faced Michael Bisping on August 23, 2014, at UFC Fight Night 48. After an even start, Le was cut around both eyes in the second round, as Bisping began to land the more powerful strikes. Bisping eventually won the one sided fight via TKO in the fourth round. Following the fight, Le tested positive for elevated levels of HGH and was subsequently suspended from competition for nine months. However, after reevaluating the evidence against Le, the UFC increased his suspension to 12 months. There has been some dispute of the test, as the testing laboratory in question was not WADA-approved, did not do the appropriate HGH test, and destroyed the blood sample before confirmatory tests could be done. Ultimately, on October 21, the UFC reversed their decision and rescinded Le’s suspension in light of the aforementioned flaws. On December 3, 2014, Le told the media that he instructed his manager to request Le’s release from UFC due to the drug-test dispute.

On December 16, 2014, Le was listed as one of three MMA fighters who filed a class-action lawsuit against Zuffa, LLC., the parent company of the UFC. The suit alleges that the UFC participated in anti-competitive practices that hindered fighters and their mixed martial arts careers. At the time Le was the only active fighter on the organization’s roster to be involved in the lawsuit.

In 2014, he starred in Puncture Wounds, an action film directed by Giorgio Serafini, co-directed and written by James Coyne.

On January 20, 2015, his manager, Gary Ibarra, announced to the media that Le had retired from MMA. Le’s decision came after reconsidering his career with his family. He had previously expressed his lack of desire to fight in the UFC and contemplated retirement following the performance-enhancing drug disputes he had with the promotion in 2014. Le believed that the UFC owed him an apology for accusing him of using drugs when the test results later turned out to be faulty. Le, however, said that his retirement was only in MMA. He talked about the possibility of returning to professional kickboxing competitions, where he was active prior to his MMA debut.

In 2015, he appeared as an abbot in the AMC TV series Into the Badlands.