23rd World Science Fiction Convention

Loncon II, the 23rd World Science Fiction Convention
GenreScience fiction
Dates27–30 August 1965
VenueMount Royal Hotel
Location(s)London
CountryUnited Kingdom
Attendance~350
Filing statusNon-profit

The 23rd World Science Fiction Convention (Worldcon), also known as Loncon II, was held on 27–30 August 1965 at the Mount Royal Hotel in London, United Kingdom. It was the second Worldcon to be held in London, following the original Loncon in 1957.

The chairman was Ella Parker.