The Temple of Elemental Evil may be an option if you're looking for a turn-based, party-based, top-down isometrics D&D game. You can create a druid as one of your starting characters, and I believe there are two recruitable NPC druids in the game.

The Dark Eye games: Drakensang dilogy, Realms of Arkania trilogy.

Neverwinter Nights 1 have druids that are quite fun to play since you can shapeshift into an animal and then just be a treehugger the rest of the time.

You'll find plenty here
https://tvtropes.org/pmwiki/pmwiki.php/Main/Druid

TVtropes is the way to go for this kind of search IMHO

The Fall of the Dungeon Guardians has druid as playable class

Glastonbury festival?! O___o

Nobody mentioned Icewind Dale so far. How come?

Just be warned that that particular site can be a time sink.

(One suggestion: Impose a limit on how deeply you follow links when you browse TVtropes.)

https://www.gog.com/forum/general/games_with_playable_druids/post4

Now that makes sense.

Icewind Dale is one of the few games where Druids are one of the most fun classes to play. In the BG games they were just tedious.
Diablo 2's Druid is nice too: only D2 class I didn't like was the Necro.
Might&Magic 6's Druid was quite playable too.

Neverwinter Nights and Diablo 2.

In Battle for Wesnoth there are elf druids. The base game is a TBS so doesnt quite fit the OP. But there are addons (mods are called 'addon' there) which (far as I remember) fit better: I think there is at least one where the main protagonist is an elf druid. And I think one other where you have an RPG like main protagonist similar to a druid. Then there are RPG addons - there are probably some where you can play druids too.

Define what a 'druid' is.

Diablo 2, the druid summons a few animals and... little else that stands out.

D&D/Pathfinder, they summon but they are also shapeshifters. But moreso the non-combat aspects are far more in depth.

I'd think a huge amount of native americans are closer to druids than what you'd see as defined in games; aka living off the land, working with plants, etc.