Clerics get two domains (obviously) and domain spell slots, though many of their archetypes give up one of their domains.
Druids can choose to get one domain and domain spell slots, though theirs is from a limited list.
Inquisitors get access to one domain, though they do not gain domain spell slots.
The Divine Hunter Archetype gets access to one domain, but no domain spell slots. However, they add their domain spells to their spells known.
The Reliquarian Occultist Archetype gets access to one domain , but no domain slots. However, they add their domain spells to their spells known.
The Sacred Servant Paladin Archetype gets access to one domain and gets domain spell slots.
The Temple Champion Paladin Archetype gets access to the 1st-level power of one domain, but no further powers and no domain spells.
The Emissary Familiar Archetypes can use the 1st-level power of one domain once per day.
Anyone can access the 1st-level power of one domain and, at higher levels the second power of that domain, via variant multiclassing.
So if you genuinely want to build around a domain, that's perfectly possible. Some have really really nice powers, after all.
Ooh, Sacred Servant is right along the lines I'm looking for! Mucho thanks!
And.... drumroll.... it looks I roped someone into being DM of a 'Distant Worlds' Pathfinder Campaign!