Assuming you're applying from the US (which you will have to do if you don't have a non-visitor visa for the UK), yes, the financial requirement is just for your British fiancé--so s/he'll have to earn at least £18,600 annually (which you can meet through a couple different ways, depending on how your fiancé is paid).
If you can qualify through the savings route (having £62,500 in savings for at least 6 months), though, it's different--the money can be in your name, your fiancé's name or in a joint account. I'm not certain about whether the savings can be over a few different accounts--say, £30,000 in yours and the rest in your fiancé's--but I'm sure someone will be able to confirm that.
If you can go the savings route, you should, as it's easiest to document, but of course not many people can due to the high financial requirement.
If you have any other questions, do post them! If you put them in the main board, they'll get attention faster