Isles | class="note" | | class="note" | |- class="vcard" | class="fn org" | Ornsay | class="adr" | Highland | class="note" | | class="note" | |- class="vcard" | class="fn org" | Ornsby Hill | class="adr" | Durham | class="note" | | class="note" | |- class="vcard" | class="fn org" | Oronsay | class="adr" | Argyll and Bute | class="note" | | class="note" | |- class="vcard" | class="fn org" | Oronsay (Loch Bracadale) | class="adr" | Highland | class="note" | | class="note" | |- class="vcard" | class="fn org" | Oronsay (Loch Sunart) | class="adr" | Highland | class="note" | | class="note" | |- class="vcard" | class="fn org" | Oronsay (Outer Hebrides) | class="adr" | Western Isles | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orosay (South Uist) | class="adr" | Western Isles | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orosay (Barra) | class="adr" | Western Isles | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orpington | class="adr" | Bromley | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orrell | class="adr" | Sefton | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orrell | class="adr" | Wigan | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orrell Post | class="adr" | Wigan | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orrisdale | class="adr" | Isle of Man | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orrock | class="adr" | Fife | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orsay | class="adr" | Argyll and Bute | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orsett | class="adr" | Essex | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orsett Heath | class="adr" | Essex | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orslow | class="adr" | Staffordshire | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orston | class="adr" | Nottinghamshire | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orthwaite | class="adr" | Cumbria | class="note" | | class="note" | |- class="vcard" | class="fn org" | Ortner | class="adr" | Lancashire | class="note" | | class="note" | |- class="vcard" | class="fn org" | Orton | class="adr" | Cumbria | class="note" | |