Charles Johnson competed for the United States at the 1992 Barcelona Olympics. He is one of only a handful of black or African-American catchers to play in the majors over the past several decades, probably having the most successful career of any since Roy Campanella and Elston Howard.

He was an All-American at the University of Miami and was an All-Star in AA in 1994. He was a first round draft pick twice, first in 1989, when he was chosen 10th overall by the Montreal Expos coming out of high school, and again in 1992, when he was the Florida Marlins' first-ever draft pick, one year before they played their inaugural season.

Johnson's strongest year offensively was 2000, when (split between two teams) he slugged .582 with 31 home runs. He also hit quite well in the 1997 World Series, with a .357 batting average. In the Series, he hit seventh in the lineup when at home and eighth in the lineup when in Cleveland. Johnson's 2-run homer off Jose Ibar was the big blow in Baltimore's 3-2 win over Cuba in game one of the 1999 Baltimore Orioles-Cuban National Team Exhibition Series.