Lough is a surname of Scottish or Irish origin, meaning lake or sea inlet. Notable people with the surname include:

• Adam Bhala Lough (born 1979), American film director and screenwriter
• Dorian Lough (born 1966), English actor
• Ernest Lough (1911–2000), English boy soprano ("O for the Wings of a Dove")
• Ida Lough (1903–1985), New Zealand tapestry maker
• John Graham Lough (1798–1876), English sculptor
• John Lough (1913–2000), English scholar of French literature and history, professor at Durham University
• Rodney Lough Jr. (born 1960), American wilderness photographer

• Frederick Charles Lough (1916–2002), U.S. Army brigadier general in Italy in World War II
• Maxon S. Lough (1886–1964), U.S. Army brigadier general in the Philippines in World War II

• Janice Lough, climate scientist at the Australian Institute of Marine Science
• Roger Lough, Chief Defence Scientist of Australia 2003–2008

• David Lough (born 1986), American baseball player
• Gary Lough (born 1970), British middle distance runner
• Nicole Lough (born 1995), British Paralympic swimmer
• Peter Lough (born 1975), Canadian lacrosse player
• Tom Lough (born 1942), American pentathlete
• William Lough (1886–1939), Australian cricketer

• Lumley Lough (1832–1896), Archdeacon of Bermuda
• Thomas Lough (1850–1922), Irish-British politician; MP 1892–1918
• William H. Lough (1881–1950s), American economist

• Loch (surname)