Carroll William Sembera (July 26, 1941 – June 15, 2005) was an American professional baseball relief pitcher, who played in Major League Baseball (MLB) for the Houston Astros (1965–67) and Montreal Expos (1969–70). Sembera batted and threw right-handed.
In a five-season career, Sembera posted a 3–11 record with a 4.70 ERA and six saves in 99 games pitched.
Sembera made his MLB debut with the Houston Astros in 1965 at the age of 23. In 1967, he recorded career-highs in games (45), innings pitched (59.2) and games finished (15). Sembera also pitched for the Montreal Expos in 1969 and 1970. Sembera earned the first save in Expos history on opening day in 1969
Following his career as a player, Sembera scouted for the Major League Scouting Bureau and with the Seattle Mariners for eleven years.
Sembera died in his hometown of Shiner, Texas, at the age of 63.