There are spells that can remove stunning.

There is at least one spell that can remove the stunned condition: power word heal. It is 9th level, however.

All stun effect require an initial saving throw.

I couldn't find any spell, class feature, or monster ability that could inflict the stunned condition automatically. All of them only apply the condition if an initial saving throw is failed. Anything that improves or gives advantage to those saving throws will thus help prevent the stun from occurring.

Aura of purity is such a spell; it doesn't remove the stunned condition, but does bestow advantage on saves against it.

Not all stun effects require a save to end.

Some stun effects, like the Monk's stunning strike, an otyugh's tentacle slam attack, an allip's howling babble, or a siren's stupefying touch, don't end on a save; they just end on the next turn.

The stun effect of the divine word spell is the same, except it lasts for an hour(!) with no chance of ending it early if the initial save is failed.

There are spells that can remove stunning.

There is at least one spell that can remove the stunned condition: power word heal. It is 9th level, however.

All stun effects require an initial saving throw.

I couldn't find any spell, class feature, or monster ability that could inflict the stunned condition automatically. All of them only apply the condition if an initial saving throw is failed. Anything that improves or gives advantage to those saving throws will thus help prevent the stun from occurring.

Aura of purity is such a spell; it doesn't remove the stunned condition, but does bestow advantage on saves against it.

Not all stun effects require a save to end.

Some stun effects, like the Monk's stunning strike, an otyugh's tentacle slam attack, an allip's howling babble, or a siren's stupefying touch, don't end on a save; they just end on the next turn.

The stun effect of the divine word spell is the same, except it lasts for an hour(!) with no chance of ending it early if the initial save is failed.

There are spells that can remove or help resist stunning.

There is at least one spell that can remove the stunned condition: power word heal. It is 9th level, however.

Aura of purity doesn't remove the stunned condition, but does bestow advantage on saves against it.

There are spells that can remove stunning.

There is at least one spell that can remove the stunned condition: power word heal. It is 9th level, however.

All stun effect require an initial saving throw.

I couldn't find any spell, class feature, or monster ability that could inflict the stunned condition automatically. All of them only apply the condition if an initial saving throw is failed. Anything that improves or gives advantage to those saving throws will thus help prevent the stun from occurring.

Aura of purity is such a spell; it doesn't remove the stunned condition, but does bestow advantage on saves against it.

Not all stun effects require a save to end.

Some stun effects, like the Monk's stunning strike, an otyugh's tentacle slam attack, an allip's howling babble, or a siren's stupefying touch, don't end on a save; they just end on the next turn.

The stun effect of the divine word spell is the same, except it lasts for an hour(!) with no chance of ending it early if the initial save is failed.