Mount's Bay is a bay on the English Channel coast of Cornwall, United Kingdom.
Mount's Bay or Mounts Bay may also refer to:
Mounts Bay RFC, a defunct rugby club formerly based in Penzance Mounts Bay Road, Perth, Western Australia Mounts Bay, in the Swan River Estuary, Perth HMS Mounts Bay (K627), a Royal Navy ship RFA Mounts Bay (L3008), a Royal Fleet auxiliary ship