John Bayard Taylor Campbell III is an American politician who served as a U.S. representative from California from 2005 to 2015. A member of the Republican Party, he previously served in the California State Assembly (2000–2004) and California State Senate (2004–2005). In Congress, Campbell represented the state's 48th congressional district for four terms and 45th congressional district for one term. On June 27, 2013, he announced that he would not seek reelection in 2014.

California's 48th congressional district is a congressional district in the U.S. state of California based in San Diego County in Southern California as well as Murrieta and Temecula in southwestern Riverside County. It is currently represented by Republican Darrell Issa.