https://www.theguardian.com/culture/2026/oct/23/oldest-pubs-inns-historic-england-archaeologist
The Green Dragon at Hardraw claims to date from the 13th century and Robin Hood bathed in the waterfall out back. Sadly, only part of this can be verified - Kevin Cosner did bathe in the waterfall :)
I'm surprised Ye Olde Trip to Jerusalem (https://www.greeneking.co.uk/pubs/nottinghamshire/ye-olde-trip-to-jerusalem) doesn't make it on his list. Admittedly, dendrochronology does not work too well on caves.
:P
The Green Dragon was established in Hobbiton in the Third Age, so that makes it really old.
And serve a mean pint according to Sam