Chan Ho Park was born in Gongju, South Korea, on June 30, 1973. As a high school player in South Korea, he won team Most Valuable Player honors three consecutive seasons at Gongju High School in Gongju, South Korea. He also was named the MVP at four national prep tournaments.

Park was a member of the 1992 and 1993 South Korea national baseball team. He posted a 2.76 ERA in helping South Korea earn the silver medal at the Asian Baseball Championship in 1993. He also competed in 1993 Summer Universiade, and led his team to the silver medal.

Park was a sophomore at Hanyang University, Seoul in 1994 when he was signed by the Los Angeles Dodgers as an amateur free agent.

Park made his professional debut for the Dodgers on April 8, 1994 against the Atlanta Braves as a reliever, working one inning (a game in which the Dodgers were no-hit by the Braves’ Kent Mercker).

With the Albuquerque Dukes in 1995 he was fourth in the Pacific Coast League in strikeouts with 101, and averaged 8.26 strikeouts per 9 innings, the top mark among all Class AAA pitchers. He was selected by Baseball America as the 2nd best Dodgers prospect after the season with the best fastball in the PCL. He recorded his first Major League start on October 1 against the San Diego Padres after receiving a September call-up.

In 1996, his first full season with the Dodgers, he went 5–5 with a 3.64 ERA in 48 games (10 starts). He recorded his first win on April 6 against the Chicago Cubs.

Park had a breakout season in 1997 as he became a full-time starter. He tied for the team lead in victories, while posting a 14–8 record and a 3.38 ERA in 32 appearances, 29 of them starts.

In 1998, he was 15–9 with a 3.71 ERA in 34 starts and struck out 191 batters in 220.2 innings. After the season, he led the South Korean national team to the gold medal in the Asian Games, beating Japan in the final match.

In 1999, he struggled in the rotation with 13–11 with a 5.23 ERA. On April 23, 1999 he became the only pitcher in the history of baseball to allow two grand slams in the same inning and to the same player, Fernando Tatís of the St. Louis Cardinals. There are two more pitchers in the history of baseball who allowed two grand slams in the same game – Jack Morris, and more recently, Brandon Backe – but to different hitters in different innings. He also walked 100 batters in only 194 innings. On June 5, 1999, Park was involved in an on-field brawl at Dodger Stadium with Anaheim Angels pitcher Tim Belcher. Park attacked Belcher after being tagged out after a bunt play. Park’s said that Belcher had tagged him too hard on the just-concluded play and asked him about the incident. According to Park, Belcher replied with racist comments causing Park to kick him.

In 2000, he ranked second in strikeouts with 217, second in opposing batting average (.214), and lowest in allowed hits per nine innings. despite second in allowing bases on balls (124) in the National League. He finished the season 18–10 with a 3.27 ERA, the best totals of his entire career. He also tossed his first career complete game shutout on September 29, against the San Diego Padres. Park was also named the Dodgers opening day starter for the 2001 season and tossed the Dodgers first season opening shutout since 1981. He was 15–11 with a 3.50 ERA during the season and was selected to appear in the 2001 Major League Baseball All-Star Game, where he pitched one inning, allowed a home run to Cal Ripken, Jr. and was charged with the loss. Park gave up Barry Bonds’ record-breaking 71st and 72nd homers on October 5 against the San Francisco Giants.

On July 29, 2005, he was traded by the Rangers to the San Diego Padres in exchange for Phil Nevin. Padres fans had hoped that Park could repeat his previous success by playing in pitcher-friendly Petco Park.

In the 2005 season, his combined record was 12-8, despite a 5.74 ERA. In the 2006 season, Park was reunited with his former Texas Rangers teammate and friend Chris Young, who was traded to the Padres in exchange for Akinori Otsuka. Park started the season as a reliever but soon he became a starter. On July 31, he suffered from intestinal bleeding and was placed on the disabled list. Several of his teammates, including Jake Peavy, Woody Williams, Chris Young, and Alan Embree, offered to donate their blood, but Park graciously refused their offer, as they were vital members of the team. Park accepted blood transfusions, that came, in part, from Jake Peavy’s wife Katie and Kelly Calabrese, Padres’ team massage therapist. However, Park’s recovery did not last long as he suffered from another episode of intestinal bleeding on August 21. He was hospitalized again, this time along with his wife Rie, who was about to deliver their first child. A very thorough medical examination revealed that Park was suffering from a congenital defect called Meckel’s diverticulum. Park had a successful surgery and only six days later his wife delivered a healthy baby daughter at the same hospital.

Between the 2005 season and the 2006 season, Park represented South Korea in the World Baseball Classic. In the Asia Round games against Taiwan and Japan, Park made appearances as a closing pitcher, shutting out the opposing lineups. He made another appearance as a closer in the semifinal game against Mexico, in which he again shut out his opposing hitters. His performance made San Diego Padres’ manager Bruce Bochy believe that Park can be used as an effective reliever as well as a starter. Park later said that Padres’ closer Trevor Hoffman taught him how to focus in a relief situation. With his shutout performance in 10 innings and three saves, Korea finished the World Baseball Classic in third place and Park was selected to the WBC All-Star team along with his teammate Lee Seung-yeop and Team Korea’s captain Lee Jong-beom.

Park married Korean-Japanese socialite Ri-hye Park on November 29, 2005. An ethnic Korean, she grew up in Japan and went to culinary school in New York. She is publicly known as a semi-professional chef, writer and the only daughter of Japan’s 76th richest man according to The Philadelphia Inquirer. In spring 2009, Ri-hye released a best-selling cookbook in South Korea whose proceeds went to children’s charities on behalf of the Chan Ho Park Dream Foundation. Park and his wife have three daughters.

The San Diego Padres advanced to the post-season and Park joined the post-season roster. On October 3, 2006, Park made his first career post-season appearance in Game 1 of the National League Division Series against the St. Louis Cardinals as a reliever. He also had career-high season batting average of .268 from 41 at bats.

On February 8, 2007, the Yonhap news agency and New York Daily News reported that Park had signed a one-year, $3 million contract with the New York Mets and would report to the Mets’ spring training facility in Port St. Lucie, Florida to compete for a starting rotation spot. The Mets sent him down to Triple-A New Orleans following his poor spring performance. On April 30, 2007, Park was called up from Triple-A New Orleans to start for the injured Orlando Hernández. In that sole game, he gave up 7 earned runs in 4 innings. On May 3, 2007, Park was sent back down to Triple-A New Orleans. He was designated for assignment on June 4, 2007.

On June 12, 2007, he signed a minor league deal with the Houston Astros. Astros Manager Phil Garner said “Park will have a few starts at Triple-A Round Rock before the Astros decide whether to call him up.” Park compiled a 2–10 record over 15 starts with Round Rock, failing to earn a spot on the Astros’ 40-man roster.

On November 8, 2007, Park accepted an offer from his original team, the Los Angeles Dodgers, to attend spring training as a non-roster invitee. On November 28, 2007, Park asked to be let go by the Dodgers to play for the Korean team. After pitching with no health issues for the Korean National team, the contract was finalized on December 6, 2007. Despite being considered a long shot for the fifth starter’s role, Park pitched very well, but was ultimately passed over for right-hander Esteban Loaiza. He was eventually reassigned to the minor leagues on March 30, 2008. Faced with the problem of a fatigued and depleted pitching staff three games later, the Dodgers purchased Park’s minor league contract on April 2, 2008.

On May 17, 2008, Park made his first start as a Dodger since 2001 against the Los Angeles Angels of Anaheim. He allowed two runs (one earned run) in four innings with no decision. This game turned out to be a historic one as for the first time in MLB history, all three Dodgers pitchers who pitched in this game (Park, Hong-Chih Kuo, and Takashi Saito) were of Asian origin. The Dodgers won it 6–3.

On June 21, 2008, Park started against the Cleveland Indians at the Dodger Stadium and joined Kevin Brown, Al Leiter, Javier Vázquez, and Jamie Moyer as the only pitchers to start a game against all 30 Major League teams. In addition to making history, he had a decent outing, with 9 strikeouts in 5 innings pitched, although this was overshadowed when he gave up a solo home run to Cleveland Indians pitcher CC Sabathia.

In December 2009 it was announced that Chan Ho Park was suing his former Dodger teammate Chad Kreuter in Los Angeles Superior Court, in which he claimed Kreuter breached repayment of a $460,000 promissory note issued in October 2005.

On February 28, 2010, Park signed a one-year contract worth $1.2 million with $300,000 incentives with the New York Yankees. Chan Ho Park decided to play for the Yankees after rejecting an offer of around $3 million per year from the Philadelphia Phillies.

Park got off to a poor start in 2010. In a widely circulated YouTube clip, he blamed his poor performance in one April appearance on a case of diarrhea. After struggling with a 5.60 ERA., Park was designated for assignment on July 31, 2010. On August 4, 2010, Park was claimed off waivers by the Pittsburgh Pirates. On October 1, Park recorded a record for most wins by an Asian born pitcher in MLB history, tossing three scoreless innings for his 124th career victory. He passed Hideo Nomo for the most ever by an Asian-born pitcher. He became a free agent at the end of the season.

On December 20, 2010, Park signed one-year deal with the Orix Buffaloes of Nippon Professional Baseball for the 2011 season.

On November 24, 2011, Park signed one-year deal with the Hanwha Eagles of Korea Baseball Organization for the 2012 season.

On December 20, 2011 Park announced that he would guarantee a minimum of $35.5k (₩40 million) of his salary to fund the development of amateur baseball in South Korea. His contract bonus has potential earnings at up to $550,000 (₩600 million) in which Park would donate 100% of this salary to fund efforts to build amateur baseball with youth in the country. Park posted a record of 5-10 with a 5.06 ERA with the Eagles.

He announced his retirement from baseball on November 30, 2012. Park had a record of 124–98 in the Major Leagues with the Dodgers, Rangers, Padres, Mets, Phillies, Yankees, and Pirates.

In 2015, he and Yang Hak-seon lit the cauldron for the 2015 Summer Universiade held in Gwangju, South Korea.