Are Super Mario and LoZ in the same universe?

[DekuNut]

You should definitley play Mario RPG. It's solid, and it really feels like both the RPG series that came out afterwards merged into one.
Personally, I don't think they're in the same world, but they're definitely connected through the multiverse, as established by Smash Bros. Link's Awakening can be explained away because that's a dreamworld, a very similar explanation as can be used for everything in Kirby's Great Cave Offensive (since all Kirby games take place in Dreamland). Notably, Kirby is the other major game that is represented in Link's Awakening, with the "Anti-Kirby" miniboss. Probably some relationship there.
There's also the connection of Wart/Mamu, who was in Link's Awakening and Doki Doki Mario Club, both of which are established to take palce in Dream Worlds. There's probably some connection there that can be made, but the difference in physics, world design, cosmology and just series logic make me think that they don't take place in the same universe.

 

[Requiem Of Spirit]

I voted "No" because I don't think they exist in the same universe. I mean, yeah, there are references and cameos here and there in both Mario and Zelda games but I think that's all they are: easter eggs.

I mean, by that same rule there would be a big universe where Mario, TLoZ, Starfox (there was a starfox enemy spaceship hidden in the code of OoT in the Gamecube) and Sonic (ik it's not a Nintendo IP but there was a Zelda themed DLC level in Sonic The Lost World)

would all somehow be in the same universe.
I think this is highly unlikely.

 

[Ryuu Kage Desu]

I subscribe to the idea that the Mario games, or at least the vast majority of them, are plays. This means that what we do see is not in the Zelda universe, but plays and actors could be. So I would give it a soft yes, but what's the point?