Londynn is a modern American spelling of London, the British capital, whose Roman name Londinium is of uncertain, probably Celtic origin and is sometimes read as "place at the unfordable river". The doubled n follows the pattern of Brooklynn and Oaklynn and marks the name clearly as a girl's. Londynn stood at number 1069 in 2015, peaked at number 1057 in 2020 and ranks 1789 in 2025.