Swayze was born in Houston, Texas, the son of Patricia "Patsy" Yvonne Helen (née Karnes) — a choreographer, dance instructor, and dancer — and Jesse Wayne Swayze, an engineering drafter. According to his website, he is of English, Polish, Irish and Apache descent. His brother, Don Swayze, is also an actor.

Until age 20, Swayze lived in the Oak Forest neighborhood of Houston, where he attended St. Rose of Lima Catholic School, Oak Forest Elementary School, Black Middle School, and Waltrip High School. During this time, he also pursued multiple artistic and athletic skills, such as ice skating, classical ballet, and acting in school plays. He studied gymnastics at nearby San Jacinto College for two years.

In 1972 he moved to New York City to complete his formal dance training at the Harkness and Joffrey ballet schools.

Swayze's first professional appearance was as a dancer for Disney on Parade. He starred as "Danny Zuko" in the Broadway production of Grease before his debut film role as "Ace" in Skatetown, U.S.A. (1979). He also appeared as Pvt. Sturgis in the M*A*S*H episode "Blood Brothers" (Episode 9.18, April 6, 1981). Swayze became known to the filming industry after appearing in The Outsiders (1983), as the older brother of C. Thomas Howell and Rob Lowe. Swayze, Howell, and Howell's friend Darren Dalton reunited in Red Dawn the next year, and Lowe and Swayze reunited in Youngblood, where he was considered a member of the Brat Pack, but his first major success was in the 1985 television miniseries North and South, which was set during the American Civil War.

His real breakthrough to stardom came with his performance as the dance instructor in the 1987 film Dirty Dancing, alongside his Red Dawn costar, Jennifer Grey. His earlier ballet experience came to good use in this film. Dirty Dancing was a low-budget project that was intended to be shown in theaters for one weekend only and then go straight to video, but it became a surprise hit and achieved massive international success. It was the first film to sell one million copies on video, and as of 2007, has earned over US$ 300-million worldwide and spawned several alternate versions, ranging from a television series to stage productions to a computer game. Swayze received a Golden Globe Award nomination for the role and also sang one of the songs on the soundtrack, "She's Like the Wind", which he had originally cowritten with Stacy Widelitz for the film Grandview, U.S.A. The song became a top ten hit and has been covered by other artists, such as David Hasselhoff, and in 2006 was converted into a hip-hop version by Lumidee, who took it to the top of the charts in Germany.

After Dirty Dancing, Swayze found himself heavily typecast as beefcake and appeared in several flops, of which Road House (1989) was the most successful. His biggest hit came in 1990, when he starred in Ghost with Demi Moore and Whoopi Goldberg. This role had considerable cultural impact, and modern hip-hop lyrics routinely use the phrase "I'm Swayze" (meaning "I'm ghost" which is in turn slang for "I'm leaving") in reference to that film (for more info, see the "Cultural Impact" section of the movie Ghost). In 1991, he starred alongside Youngblood castmate Keanu Reeves in another major action hit, Point Break, and was also chosen by People magazine as that year's "Sexiest Man Alive".

Swayze was seriously injured in 1996 while filming HBO's Letters from a Killer in the Ione area, when he fell from a horse and hit a tree. Both of his legs were broken and he suffered four detached tendons in his shoulder. Filming was suspended for two months, but the film aired in 1999. Swayze recovered from his injuries, but had trouble resuming his career until 2000, when he costarred in Waking Up in Reno, with Billy Bob Thornton and Charlize Theron, and in Forever Lulu, with Melanie Griffith.

In 2001, he appeared in Donnie Darko, where he played a motivational speaker and closet pedophile, and in 2004, he played Allan Quatermain in King Solomon's Mines. He also had a cameo appearance in the Dirty Dancing sequel, Dirty Dancing: Havana Nights (2004) as an unnamed dance instructor.

He made his London stage debut in the musical Guys and Dolls as Nathan Detroit on July 27, 2006 alongside Neil Jerzak, and remained in the role until November 25, 2006. His previous appearances on the Broadway stage had included productions of Goodtime Charley (1975) and Chicago (2003).

Swayze's latest starring role was in the film Christmas in Wonderland (2007). In August 2007, Swayze played an aging rock star in the upcoming film "Powder Blue" (slated for 2008 release), costarring his younger brother Don in their first film together. Patrick is currently working on an A&E pilot/FBI drama The Beast, filming in Chicago in summer 2008; he will play FBI Agent Charles Barker. The Beast is scheduled to air in early 2009.

Swayze has been married to Lisa Niemi since 1975. The couple first met in 1970, when Lisa, then age 15, was taking dance lessons from Swayze's mother. Niemi was born in Houston, Texas to her Finnish-American parents, Edmond Melvin Haapaniemi and Edna Karin Hyttinen.

As a reaction to his father's death by heart attack in 1982, Swayze began to drink heavily. His sister Vicky passed away in 1994, leading him to seek treatment for alcoholism. After initial recovery, he temporarily withdrew from show business, retreating to his ranches in California and Las Vegas, New Mexico to breed Arabian horses. His best-known horse was the late Tammen, a chestnut Arabian stallion.

Swayze, a certificated airplane pilot with an instrument rating, made the news again on June 1, 2000, while flying with his dogs in his twin-engine Cessna from Van Nuys, California to Las Vegas, New Mexico. His plane developed a pressurization problem over northern Arizona, causing Swayze to make a precautionary landing on a dirt road in a housing complex in Prescott Valley. The plane's right wing struck a light pole that he hadn't seen from the air, but Swayze was unharmed. He locked up the cockpit, left it parked in the subdivision, and obtained a ride (with his dogs) from a passing vehicle, allegedly in order to telephone the authorities. According to the police report, witnesses said that Swayze appeared to be extremely intoxicated and asked for help to remove evidence (including an open bottle of wine and a 30-pack of beer) from the crash site. He also made himself unavailable to police for several hours. It was later determined that the alcohol in question was not in the cabin but stored in external storage compartments inaccessible in flight and that the alleged "intoxication" was due to the effects of hypoxia during descent.

He has followed several spiritual traditions. Brought up a Roman Catholic, he has also studied Bahá'í, Buddhism, and Scientology.

Swayze was diagnosed with pancreatic cancer in late January 2008, and has been undergoing chemotherapy and other treatments at the Stanford University Medical Center. A March 5, 2008 Reuters article reports that Swayze "has a very limited amount of disease, and he appears to be responding well to treatment thus far". Swayze's doctor has confirmed the actor has been diagnosed with pancreatic cancer, but insists he's not as close to death as reports suggest. Specifically, Swayze was diagnosed with a type of pancreatic tumor called Intraductal Papillary Mucinous Neoplasm (IPMN).

In early May 2008, it was widely reported in a number of tabloids that Swayze had undergone surgery to remove part of his stomach after the spread of the cancer, and that he had rewritten his will, transferring his property to his wife. In a statement made on May 28, Swayze said that he continues to respond well to treatment at Stanford University Medical Center. In late May 2008 he was seen at a Los Angeles Lakers basketball game, his first public appearance since his diagnosis.

In late July 2008, six months after allegedly being given just weeks to live by medical experts, Swayze was seen in Los Angeles LAX airport appearing healthy. When asked about his condition, he told reporters "I'm cooking. I'm a miracle dude, I don't know why".

Swayze appeared on the ABC, NBC, and CBS simulcast of Stand Up to Cancer in September 2008, to appeal to the general public for donations for the initiative. Swayze said to a standing ovation, "I dream that the word 'cure' will no longer be followed by the words 'it's impossible'. Together we can make a world where cancer no longer means living with fear, without hope, or worse". After the show ended, Swayze lingered onstage and talked to other cancer survivors; executive producer Laura Ziskin said, "He said a beautiful thing: 'I'm just an individual living with cancer.' That's how he wants to be thought of. He's in a fight, but he's a fighter".

Swayze died "with family at his side" on September 14, 2009, at age 57, twenty months after being diagnosed.