Bistra (; ) is a commune located in Alba County, Transylvania, Romania. It has a population of 4,340 as of 2021. It is composed of 35 villages: AroneÃÂti, BÃÂleÃÂti, BÃÂleÃÂti-CÃÂtun, BârleÃÂti, Bistra, Cheleteni, CiuldeÃÂti, CreÃÂeÃÂti, Dâmbureni, Dealu Muntelui, DurÃÂÃÂti, GÃÂneÃÂti, Gârde, HodiÃÂeÃÂti, HudriceÃÂti, Lipaia, Lunca LargÃÂ, Lunca Merilor, MihÃÂieÃÂti, NÃÂmaÃÂ, NovÃÂceÃÂti, PerjeÃÂti, Poiana, Poiu, RÃÂtitiÃÂ, Runcuri, SÃÂlÃÂgeÃÂti, ÃÂtefanca, ÃÂÃÂrÃÂneÃÂti, TolÃÂceÃÂti, Tomnatec, TriÃÂoreÃÂti, VârÃÂi-Rontu, VârÃÂii Mari, and VârÃÂii Mici.
The commune is situated in the northwest corner of Alba County. It covers a surface of (about 1.8% of the total area of the county), making it the largest commune in Romania by surface area. Bistra is crossed from West to East for a length of by the ArieÃÂ River. It is surrounded to the SE by the TrascÃÂu Mountains, the SW by the Metaliferi Mountains and to the NE by the GilÃÂu Mountains, with as the highest peak, at .