In baseball, a setup pitcher (or set-up pitcher, sometimes called the setup man) is a relief pitcher who regularly pitches before the closer. They commonly pitch the 8th inning, with the closer pitching the 9th.

The concept of a team having a defined setup pitcher is a relatively new one which has been aided by the addition of the statistical category of holds. The role, however, remains a flexible and sometimes ill-defined one. Setup pitchers, unlike closers, commonly appear in games where their team is tied or even behind, making the designation of setup pitcher representative of only a certain number - perhaps under half - of the pitcher's appearances within a season.

Teams commonly have a right-handed and a left-handed setup pitcher in their bullpens.

Notable Major League Baseball pitchers who have held the role of setup pitcher for an significant period of time include:

• Octavio Dotel
• Alan Embree
• Tom Gordon
• Paul Quantrill
• Arthur Rhodes
• Mariano Rivera
• Mike Timlin
• Duane Ward