Alexander Johnson or Alex Johnson may refer to:

• Alexander Bryan Johnson (1786–1867), British philosopher and banker
• Alexander Lange Johnson (1910–1989), Norwegian bishop
• Alexander S. Johnson (1817–1878), American jurist
• Alexander Johnson (basketball) (born 1983), American basketball player
• Alexander Johnson (figure skater) (born 1990), American figure skater
• Alexander Johnson (mathematician) (1830–1912), Canadian academic
• Alexander Johnson (pentathlete) (born 1969), Australian modern pentathlete
• Alexander D. Johnson (born 1952), American biochemist
• Alexander Johnson, lead singer of These Kids Wear Crowns
• Alex Johnson (1942–2015), American baseball player
• Alex Johnson (Australian footballer) (born 1992), Australian rules footballer
• Alex Johnson (basketball) (born 1988), Canadian basketball player
• Alex Johnson (climber) (born 1989), American rock climber
• Alex Johnson (footballer, born 1917) (1917–1944), English footballer
• A. J. Johnson (linebacker) (born 1991), American football player
• Alex Johnson (firefighter) (born 1967), British firefighter
• Alex T. Johnson, first African-American chief of staff of the U.S. Helsinki Commission
• Boris Johnson (Alexander Boris de Pfeffel Johnson, born 1964), British politician and ex-Prime Minister of the United Kingdom
• Alex Johnson (American football) (born 1968), American football Wide Receiver

• Alexander Johnston (disambiguation), several people
• Alexandra Johnson (disambiguation), multiple people
• Alexz Johnson (born 1986), Canadian singer and actor
• Hotel Alex Johnson, in Rapid City, South Dakota
• All pages with titles containing Alexander Johnson