Alex or Alec or Alexander Kennedy may refer to:

• Alexander Kennedy (martyr) (died 1539), Scottish martyr
• Alec Kennedy (1891–1959), English cricketer
• Alexander Kennedy (1847–1928), British engineer and academic
• Alexander Kennedy (physician) (1764–1827), Scottish surgeon and antiquary
• Alexander Kennedy (colonist) (1837—1936), Scottish colonist of Queensland
• Alexander Kennedy, known as Sandy Kennedy (fl. 1875–1884), Scottish footballer
• Alex Kennedy (British Army soldier), youngest British soldier to receive the Military Cross since 1945
• Alex Kennedy (footballer) (1893–1985), Australian footballer
• Alex Kennedy (rower) (born 1992), New Zealand rower
• Alex Kennedy (racing driver) (born 1992), American stock car racing driver