On July 13, 1889, Stanley Coveleski was born as Stanislaus Kowalewski in the coal-mining town of Shamokin, Pennsylvania to his parents Anthony and Antoinette Kowalewski. Coveleski described his early life at his Hall of Fame induction on July 28, 1969. "When I was twelve, I started working in the coal mines eleven hours a day, six days a week, for $3.75 a week." He worked in the mines with his four brothers, all of whom had an interest in baseball. Coveleski and his older brother Harry wanted more for their lives than being stuck in coal country. He explained, "I had a hobby of tying a can on a string to a tree and throwing stones at it for hours. I didn't know anything about baseball then, but that helped me get a contract for $250 a month." He and his brother Harry decided to escape the coalmines by using their athletic talents to start careers in baseball.

Coveleski signed his first professional contract in 1907 with the Lancaster Red Roses, a minor league team managed by Marty Hogan. In 1909, he helped the Red Roses win their first championship in the Tri-State League. Coveleski pitched in the minor leagues for a number of years. His first game in the major leagues was on September 10, 1912, at age 23, pitching with the Philadelphia Athletics. The Philadelphia Athletics gave him a five game trial, but was unable to impress. Coveleski returned to the minor leagues in 1915 and signed with the Portland Beavers. Here, he was able to turn his career around, using the spitball. A spitball is a pitch in which the pitcher applies saliva to the baseball to change its aerodynamic properties or to reduce friction between his fingers and the ball.

In 1916, Coveleski became a regular major league pitcher, signing with the Cleveland Indians. In this season, he walked only 58 batters in 232 innings, which is a tremendous demonstration of control for someone pitching the infamously difficult spitball. On May 24, 1918, Coveleski pitched 19 innings in the Indians' 3-2 victory over the New York Yankees. He pitched over 300 innings that year. Coveleski accomplished his first 20-win season in 1919.

Though the spitball was banned in 1920, Coveleski's use of the pitch was grandfathered into the rules until his retirement. In the next year, Coveleski helped guide his team to the 1920 World Series versus the Brooklyn Dodgers, then known as the Brooklyn Robins. He was credited with three of the Indians' five wins over the Robins. In those three games, Coveleski gave up only five hits in each game and walked only two batters in the twenty-seven innings. Coveleski led the Indians to win five out of seven games, and helping them win their first World Series title. Compared to other 1920 pitchers, he was first in strikeouts and finished among the top five in shut outs and walks and hits per innings pitched. Coveleski also notched 24 wins in the 1920 season.

Before the 1921 season began, the spitball was banned from being pitched in any major league game. Instead of completely abolishing the spitball, the league identified 17 spitball pitchers who were allowed to continue throwing the spitball for the remainder of their careers. Coveleski's unique spitball pitching skills got him on the list. In 1923, he led the league in ERA (earned run average) with an ERA of 2.76. Coveleski continued to play with the Cleveland Indians until he was traded to the Washington Senators on December 12, 1924. In his 1925 season with Washington, he led the major leagues in winning percentage with 20-5 record and in ERA with 2.84. Coveleski and the Senators made it to the 1925 World Series, but Coveleski was charged with two losses and ended with a defeat by the Pittsburgh Pirates. Washington released Coveleski after the 1927 season. He pitched for the New York Yankees in 1928 and played his last game as a major league baseball player on August 3 of that year. Coveleski ended his baseball career as a pitcher with a record of 215 wins and 142 losses.

After his retirement, Coveleski settled with his wife and two children in South Bend, Indiana, where he owned and operated a gas and service station. He became a popular member of his community, providing free pitching lessons to local youth in a field behind his home. On, July 28, 1969, Coveleski was inducted into the National Baseball Hall of Fame in Cooperstown, New York. In 1978, the city of South Bend established a Stanley Coveleski display at the Northern Indiana Historical Museum. The trophy case honors highlights of his career, including strikeouts of Babe Ruth, and beating Walter Johnson in one of baseball's most memorable pitching battles.

As Coveleski's health declined, he was eventually admitted into a local nursing home where he died on March 20, 1984, at the age of 95. Coveleski continued to be recognized even after his death. In 1987, the South Bend Silver Hawks, a minor league team, dedicated their stadium to Coveleski, naming it the Stanley Coveleski Regional Stadium.