My first year with a real pond, but I've always put one or more feeder goldfish from the pet store in all open buckets and containers of water, as well as my mini rice paddy garden, downspout rain garden, swales, etc. After rain, I empty any rainwater retaining containers into containers that HAVE goldfish in them.
Had a neighbor dispute going one year, and the said neighbor called and reported me to the township as source of their mosquito problems. Fortunately had a dialog going with the head of the department and he met with me when the mosquito inspector came to my garden.
Had an animated discussion with both gentlemen about my idea of an environmentally responsible organic gardenIng and mosquito control -- talking about my garden is my favorite past time
....The inspector checked my little containers and bogs, -- me dogging his footsteps and asking to see his little dipping cup and asking him to explain to me what he expected to see to judge it a fail -- and after a thorough inspection, signed off on a certificate of approval for my garden, and handed out mosquito control pamphlets to the neighbor.
All this to say, YEP! -- fish will take care of any mosquito concerns! I buy feeder goldfish and minnows like I said because they are easy and inexpensive, but I understand in some areas, you can get mosquitofish, sometimes through your local authority.
I also use Bt mosquito bits and dunks when appropriate/necessary in fish-less containers and in folds of plastic or tarp where rain could collect when we have DAYS of rain and I don't want to go out there.