Where to Find and Catch Finneon
From Pokemon Go Wiki
Finneon are found and captured in Nest and Habitat locations.
Nests
Finneon Nests are locations that consistently spawn Finneon.
Habitats
Finneon Habitats are spawn locations where Finneon is likely to be encountered, but not guaranteed the way a Nest is.
Additional Tips and Information
Best Nests
If you know a really good nest or any of the nests above is really good, list them here: