You could knock one of the Ns off the end, but that’s about the only way you’ll be shortening a name like Finn.
Famous people named Finn:
Actors Finn Jones, Finn Cole, and Finn Wolfhard; Nobel Prize winner Finn Kydland.
The Pepperidge Farm goldfish mascot’s name is Finn.
Fab Four-Letter Names For Boys, Fantastic F Names For Baby Boys, Baby Boy Names From Children’s Books, Double The Fun: Boy Names With Double Letters, Simple One-Syllable Boy Names, Boy Names People Won’t Shorten, Animal-Inspired Baby Names For Your Little Wild One, Well-Read Names From Classic Literature, Short, Sweet Baby Boy Names, Names For Baby Boys With A Whole Lot Of Badassery,