A native of Tulsa, Oklahoma, Tillis grew up in a broken family with an alcoholic father and a deeply religious mother. He dreamed about being a professional boxer after he listened to the 1964 bout between Muhammad Ali and Sonny Liston.He enlisted the help of noted trainer Ed Duncan. Tillis had an amateur record of 92-8, which included three state golden gloves and four state aau titles. He lost to future pro opponent Greg Page in the 1976 National Golden Gloves.
Tillis began his boxing career in 1978 with a first-round knockout of Ron Stephany. He won his first 20 fights with 16 knockouts. One of his most impressive early victories was a seventh-round knockout over the "Omaha Butcher" Ron Stander. Stander had fought Joe Frazier and was regarded as one of boxing's most durable fighters. Other notable wins included a knockout of the South American champion Domingo D'Elia and a points win over the sometimes dangerous fringe contender Mike Koranicki.
In 1981, Tillis fought "Hercules" Mike Weaver for the WBA World Heavyweight title. After a strong start, Tillis tired. The fight would become famous for trainer Angelo Dundee imploring Tillis to do something, asking the fighter, "do you want to be a bum all your life?" Ultimately Tillis lost a close points decision.
In June 1982 Tillis came off the floor to outpoint the hard-hitting legend Earnie Shavers but blew that momentum only a few months later, being upset by late substitute (and future world champion) Pinklon Thomas. In November 1982, Tillis fought former amateur rival Greg Page for the USBA Heavyweight title, where he knocked Page down but again tired and was the victim of an eighth-round knockout loss. Page would go on to win the world title.
Having scored four wins, Tillis challenged (future two-time world champion) Tim Witherspoon in September 1983 for the vacant North American Boxing Federation title. Tillis was shockingly bombed out in one round apparently slipping on water in the ring as Witherspoon hit him. After the fight, Tillis' trainer Angelo Dundee left him and advised him to retire as he had just suffered his third defeat in thirteen months.
Tillis got a new team and put together four wins in 1984, before challenging Carl Williams in a world title eliminator. Having decked Williams twice in the opening round, Tillis tired and was outpointed. In 1985, under the guidance of Trainer Drew Bundini Brown, he fought Joe Frazier's son and top contender Marvis Frazier. In a recurring theme, he had Frazier down in the second round but ran out of gas and was outpointed. A few months later he travelled to South Africa to fight hard-hitting ex-champ Gerrie Coetzee. Tillis was outpointed but sent Coetzee to hospital with stitches and missing teeth.
After extensive medical examination, it was discovered the reasons for Tillis' strange recurrent fatigue midway through fights was a severe allergy to the classic fighter's diet of milk and eggs. A doctor provided Tillis with a more suitable diet in the training for his upcoming fight with Mike Tyson, who was a red-hot prospect with a 20-0 (20 knockouts) record. Tillis appeared to be a new man as he exchanged with Tyson and gave the future two-time champ a very tough fight. Although ultimately outclassed, he was the first person ever to take Iron Mike the distance.
The new Tillis was short-lived however, as he travelled to Australia and lost a close decision to veteran Joe Bugner. In 1987 he was upset in eight rounds as underdog (and regular Tyson sparring partner) Michael Williams came off the floor to beat an exhausted Tillis. Later in the same year he was busted up and stopped in five rounds by future champ Frank Bruno in London, and knocked out in 10 rounds by hard-hitting Johnny DuPlooy in South Africa.
Having failed to secure a rematch with Tyson in 1988, this time for the undisputed heavyweight championship, he made one last attempt at the big time, brought in to fight reigning cruiserweight world champion Evander Holyfield, who was making a high-profile move into the heavyweight ranks. Holyfield punched out Tillis in five one-sided rounds.
Tillis resurfaced in 1991. However, his days even as a journeyman appeared over as hard-hitting (and future WBO World Champion) Tommy Morrison knocked him out in one round. His record was a mediocre 39-18-1.
Tillis fought on and off until 2001. Although he still was able to outpoint former top-flight amateur Craig Payne, a 39-year-old Tillis was stopped in six rounds by Cliff Couser in 1996.
Tillis fought his last fight in 2001, losing to clubfighter Rob Calloway when he was 44 years old.
In retirement he wrote an autobiography, [Thinkin' Big- The Story of James "Quick" Tillis- The Fightin' Cowboy]
James Tillis, received catBOX Entertainment, Inc.’s Lifetime Sports Achievement Award. Tillis, whose fighting prowess named him “quick” “the fighting cowboy” was honored with the catBOX Entertainment, Inc.’s Lifetime Sports Achievement Award, before the main event at catBOX’s professional fight card set for February 11, 2010 at Remington Park Casino in Oklahoma City, Oklahoma. http://www.catboxentertainment.com/catboxaward.html
On Feb. 12,2010, the State of Oklahoma honored one of its favorite sons, James “Quick” Tillis of Tulsa. Gov. Brad Henry signed a declaration making Feb. 12 James “Quick” Tillis Day in Oklahoma.http://www.tulsabeacon.com/?p=3684
On November 5, 2011, James "Quick" Tillis was Inducted into the Rochester Boxing Hall of Fame, receiving the "John Mastrella Integrity Award".
Tillis is married to Vanessa Williams-Tillis and [as of 2011] lives in La Luz, New Mexico. He primarily enjoys, "serving The Lord Jesus Christ, Cowboying and volunteering with amateur boxing clubs.
A film adaptation of his autobiography,["Thinkin' Big: The Story of James "Quick" Tillis- The Fightin' Cowboy], is in pre-production.