Southdown may refer to:
Southdown sheep, a breed of sheep Southdown, Cornwall, England Southdown, a suburb of Harpenden, Hertfordshire, England Southdown, New Zealand, a suburb of Auckland Southdown Motor Services, a former bus company based in Sussex, England Southdown Power Station, a power station in Auckland Southdown, a cement company acquired by Cemex
See also South Downs, England South Down (disambiguation) Down south (disambiguation) HMS Southdown