As of the 2014 season that has been done 14 times:
1) Bill Dinneen of the Boston Americans against the Pittsburgh Pirates in 1903. The World Series in 1903 was a best 5 of 9.
2) Deacon Phillippe of the Pittsburgh Pirates against the Boston Americans in 1903. Phillippe is the only pitcher to win 3 games in a Series for a losing team. The World Series in 1903 was a best 5 of 9.
3) Christy Mathewson of the New York Giants against the Philadelphia Athletics in 1905. Mathewson is the only pitcher to throw three shutouts in one World Series.
4) Babe Adams of the Pittsburgh Pirates against the Detroit Tigers in 1909.
5) Jack Coombs of the Philadelphia Athletics against the Chicago Cubs in 1910.
6) Joe Wood of the Boston Red Sox against the New York Giants in 1912.
7) Red Faber of the Chicago White Sox against the New York Giants in 1917.
8) Stan Coveleski of the Cleveland Indians against the Brooklyn Robins in 1920. The World Series in 1920 was a best 5 of 9.
9) Harry Brecheen of the St. Louis Cardinals against the Boston Red Sox in 1946.
10) Lew Burdette of the Milwaukee Braves against the New York Yankees in 1957.
11) Bob Gibson of the St. Louis Cardinals against the Boston Red Sox in 1967.
12) Mickey Lolich of the Detroit Tigers against the St. Louis Cardinals in 1968.
13) Randy Johnson of the Arizona Diamondbacks against the New York Yankees in 2001. Johnson is the only pitcher to win Game 7 in relief after having won Game 6 as a starter.
14) Madison Bumgarner of the San Francisco Giants against the Kansas City Royals in 2014. Like Randy Johnson, Bumgarner won game 7 in relief.
Randy Johnson won three World Series games in the 2001 World Series to help beat the New York Yankees 4 games to 3.
As far as the World Series goes, that was Christy Mathewson of the New York Giants in 1905. The Giants won the Series, 4 games to 1, over the Philadelphia Athletics. Not only did Mathewson win three games, he pitched three shutouts. He is the only pitcher in World Series history to throw three shutouts in one Series.
George Frazier was the losing pitcher in Games 3, 4, and 6 of the 1981 World Series, won by the Los Angeles Dodgers over the Yankees 4 games to 2.
That was Christie Matthewson, who did so in the 1905 Series.
Deacon Phillipe of the Pittsburgh Pirates threw 5 complete games in the 1903 World Series against the Boston Americans.
The first left-handed pitcher to achieve three wins in one World Series was John Tudor of the St. Louis Cardinals in the 1985 World Series against the Kansas City Royals. Tudor won Games 1, 4, and 7 of the series.
Whitey Ford started three games for the Yankees in the 1962 World Series.Game 1 - (win)Game 4 - (no decision)Game 6 - (loss)
Deacon Phillippe of the Pittsburgh Pirates was the winning pitcher in Games 3 & 4 of the 1903 World Series. He was the starter and threw complete games in both. The games were played three days apart as there was a travel day after Game 3 and then a rainout. Game 3 was played October 3 and Game 4 was played October 6.
Brian Anderson
Guy White (nicknamed Doc) who pitched in three games in the 1906 World Series and had 1 win and 1 save.
The Cubs won three games in the 1945 World Series.
Jim Palmer of the Baltimore Orioles won 1 game in each of the 1966, 1970, 1971, and 1983 World Series.