Paul E. Pfeifer (born Oct. 15, 1942, in Bucyrus, Ohio) is an American politician of the Ohio Republican party.

Pfeifer earned a bachelor of arts degree in economics, political science, and history in 1963 from Ohio State University. In 1966, he also earned a law degree from Ohio State.

From 1967 to 1970, he worked as an assistant attorney general under Ohio Attorney General William B. Saxbe. Pfeifer practiced law with the firm Cory, Brown & Pfeifer from 1973 to 1992. From 1973 to 1976, he also served as an assistant to the Crawford County, Ohio, county prosecutor.

In 1970, Pfeifer was elected to the Ohio House of Representatives. Pfeifer served as an Ohio state representative from 1971 to 1976. In 1976, he successfully ran for a seat in the Ohio Senate. Pfeifer was re-elected in 1980, 1984, and 1988. From 1983-1984, Pfeifer was minority floor leader and from 1985 to 1986, with a Republican majority in the Senate, Pfeifer begame assistant president pro tempore.

Pfeifer owns a cattle farm in Crawford County.

In 1982, Pfeifer ran for the U.S. Senate, but was defeated by incumbent Democrat Howard Metzenbaum.

In 1990, Pfeifer ran for Ohio attorney general, losing to Democrat Lee Fisher. Fisher defeated Pfeifer with a narrow margin of just over 1,200 votes. Pfeifer, claimign that there were discrepancies between the total number of ballots cast and the number of signatures in the poolling books, appealed to the Ohio Supreme Court to review the results, but the court refused.

In 1992, Pfeifer was elected to the Ohio Supreme Court, defeating John T. Patton. In 1998, he was re-elected to the court, defeating Ronald Suster. Pfeifer is unopposed in his bid for re-election in 2004.

Although a Republican, Pfeifer has often joined the Democratic minority on the court in opposing the court's conservative bloc.

Pfeifer and his wife Julia have three children and three grandchildren.