Erwin Coolidge "Bob" Porterfield (August 10, 1923 – April 28, 1980) was an American right-handed Major League Baseball pitcher.

He played for twelve seasons between 1948 and 1959 for the New York Yankees, Washington Senators, Boston Red Sox, Pittsburgh Pirates and Chicago Cubs.

Although he walked 34 and struck out only 30 batters, he threw only one wild pitch in that time so his control must not have been too much of a concern.

On June 15, 1951, he was sent with Tom Ferrick and Fred Sanford to the Senators for Bob Kuzava.

He was seventh in the league in MVP voting and was named The Sporting News Pitcher of the Year.

He led the league with 24 complete games and 9 shutouts and was also involved in a triple play on May 22.

In his appearance in the All-Star Game, he allowed one home run to Ted Kluszewski.

After his three successful seasons in which he averaged a record of 15–13, and posted a cumulative 3.14 ERA, his career quickly spiraled downward.

His 10-17 record and 4.45 ERA in 1955 prompted the Senators to trade him (along with Johnny Schmitz, Tom Umphlett, and Mickey Vernon) to the Red Sox for Karl Olson, Dick Brodowski, Tex Clevenger, Neil Chrisley, and Al Curtis (a minor leaguer) on November 8 of that year.

He actually did fairly well with the Pirates in 1958—in 37 appearances (only six starts), he posted a less-than-stellar 4–6 record, but his ERA was a solid 3.29.

He won quite a pitching duel with Curt Simmons, earning the victory in a 1–0, 11 inning bout with the Philadelphia Phillies.

He was involved in another interesting game in 1958 as well—on July 23, "Dodger Norm Larker hits a ball just inside the 1B line, which the Pirates believe to be foul.

When umpire Vic Delmore signals it fair, P Bob Porterfield picks up the ball from where it had rolled into the bullpen.

His first career home run was a grand slam, which he hit on May 5 of that year.