In 1992 he became the all time saves leader in Major League Baseball with 342, breaking Rollie Fingers previous record. Reardon's record was broken the next season by Lee Smith. He currently ranks 7th on the All-Time Saves List with 367.
After playing College Baseball for the University of Massachusetts Amherst, Reardon went undrafted and signed a Minor League contract with the New York Mets in 1977. He made his Major League debut with the Mets in 1979, and stayed with the team until 1981 when he was traded to the Montreal Expos. With the Expos, Reardon was named to the All-Star team twice (1985-1986), and led the majors in saves during the 1985 season, earning the Rolaids Relief Man of the Year Award. Jeff was traded to the Minnesota Twins for the 1987 season, and helped the Twins win the 1987 World Series. The next season he was named to his third All-Star team, and became the first pitcher in Major League Baseball history to have 40 save seasons in both the American and National Leagues. In December 1989 he signed with the Boston Red Sox, bringing him back to his home state of Massachusetts. In honor of Reardon's signing his town of birth, Dalton, Massachusetts named its athletic field in Reardon's honor.  With the Red Sox he was named to his 4th and final All-Star team in 1991, and broke Rollie Fingers all time saves record in 1992 with his 342nd save. Later that season he was traded to the Atlanta Braves. Reardon played for one year stints with the Cincinnati Reds and New York Yankees before retiring in 1994.
On December 26 2005, Reardon was taken into custody and charged by the Palm Beach Gardens, Florida Police Department for allegedly committing armed robbery at a Hamilton Jewelers store at the Gardens Mall while leaving his son Brendan unattended in the penthouse suite. . Reardon attributed his actions to the influence of antidepressants he had been taking since his son Shane Andrew Reardon died of a drug overdose on February 21, 2004 
Reardon was found not guilty of the above charges by reason of insanity . The judge ruled that because Reardon had been taking anti-depressants and mood stabilizers, and was distraught over his son's death, there was no reasonable explanation for the robbery. Reardon was not required to be committed after the ruling.
- List of Major League Baseball saves champions
- List of Major League Baseball all-time saves leaders
- Games finished
- Career statistics and player information from Baseball-Reference, or Fangraphs, or The Baseball Cube
- Baseball Library
|National League Saves Champion|
|All-Time Saves Leader|