Blackham is an English surname. Notable people with the surname include:

• Blackham baronets
• Dorothy Blackham (1896–1975), Irish illustrator, artist and teacher
• Ernest Blackham (1898–1966), English footballer
• Fred Blackham (1873–1967), Australian rules footballer
• H. J. Blackham (1903–2009), British humanist philosopher, writer and educationalist
• Jack Blackham (1854–1932), Australian cricketer
• Jeremy Blackham (born 1943), British Royal Navy officer
• Joan Blackham (1946–2020), British actress
• Joyce Blackham (1934–2018), British opera singer
• Robert J. Blackham (1868–1951), author, doctor and army officer
• Sam Blackham (1890–1956), English footballer

• Blackham, English village
• Blackham Coliseum, located in Lafayette, Louisiana