Is there a dwarven deity for whom the Light domain would be applicable? Obviously, with GM buy-in you can take any domain for any deity, but I'd prefer to create a thematically consistent character. I've been looking around, but the dwarves don't appear to have a sun god, or a fire god, or any of the usual suspects for Light domain clerics.
The setting is Forgotten Realms, and the game is D&D 5e. Since the only dwarven deity in a 5e book is Moradin, I'm open to anything from an earlier edition. Just including 5e on the question to avoid any gods who have been killed or otherwise removed from canon.
Also worth noting that while I'm open to answers like 'Moradin works for the Light domain because such-and-such', it's easy to see that Lathander (or, preferably, the dwarf version of him) is far more thematically appropriate.
Best Answer
With the release of Mordenkainen's Tome of Foes, there is a list on page 73 of dwarven deities and their domains. Berronar Truesilver and Tharmekhûl both have the Light domain. I'll leave my original answer below the break for reference in case future readers wouldn't prefer the two deities listed above.
Dugmaren Brightmantle seems like a good candidate. From the Wikipedia page:
His domain isn't strictly light, but those domains are probably more of a suggestion. It could be argued that Light would be a fitting domain for this deity. Discovery, knowledge, and enlightenment go hand-in-hand with light in certain deity systems. Alternatively, Marthammor Duin could be an option since that deity has an affinity for lightning.
Tharmekhûl could be an option as well due to being associated with fire and the light domain has quite a few fire spells.
Source: Dwarf Deities on Wikipedia