Blackmans Bay is a coastal suburb of Kingborough Council, Tasmania, Australia. It forms part of the Kingston-Blackmans Bay urban area and is a satellite town of Greater Hobart. It borders Kingston Beach to the north, Maranoa Heights and the Peter Murrell Conservation Area to the west and Howden and Tinderbox to the south.

Blackmans Bay is named after James Blackman, who occupied land there in the 1820s. Another "Blackman Bay", near Dunalley (also in Tasmania) was so named in 1642 because of the presence of Aboriginal Tasmanians.

Blackmans Bay is located on the hills surrounding a popular sandy beach.

There is a blowhole near the northern end of the beach, which has eroded and forms a large rock arch where waves can be seen coming in and crashing on the rocks. James Baynton is credited with the discovery of the blowhole when he found his lost dog whimpering at its base.

At the southern end of the beach are rocks leading to Flowerpot Point, a popular spot for fishing, although snags are an issue because of the prevalence of seaweed and rock ledges beneath the water. Beyond Flowerpot Point lies a quiet pebble beach that is accessible at low tide. The Suncoast Headlands walking track leads south via clifftops to Soldiers Rocks, dog exercise area and bushland loop walking track.

At the southern boundary of the suburb lies Fossil Cove, accessible via a steep walking track from Fossil Cove Drive.

Blackmans Bay has three primary schools from kindergarten to grade six: Blackmans Bay, Illawarra, established in the late 1980s, and the Catholic St. Aloysius.

The shopping centre Bayview Market, located centrally within the suburb, includes a supermarket, newsagency, doctor's surgery, pharmacy and a variety of other stores.

Blackmans Bay also has a set of three restaurants near the shore.

The 1830 Ross Almanack describes Blackmans Bay as "[...] several small farms. It is a very romantically situated little settlement with a fine sandy beach in front. The potatoes that grow there are as celebrated as those of Brown's River." The only families referenced in the text are the Mansfields and the Lovetts. The signal station "Mount Lewis" is said to be located next to the Lovett household.

Despite knowledge of the Bay's existence it was settled relatively late, and by 1842 only four or five families lived in the area. The road from Hobart reached Brown's River and ended in Kingston Beach, with only a sandy track over the hill connecting Kingston Beach and Blackmans Bay. One of the earliest settlers was William Sherburd who was granted 50 acres there in 1818, which he started farming in 1819. The existing oval at Blackmans Bay bears Sherburd's name.

Blackmans Bay did not develop as quickly as Brown's River or Kingston Beach, as the lack of a road or jetty made it difficult to access. Therefore the area enjoyed little development between 1830 and 1880, with farmland growth but little change in population. There were still few residents by the 1930s, with only the following six families listed as residing in the area: Ranger, Parson, Ayres, Sherburd, Chamberlain and Keeble. The area enjoyed greater growth during the post-war period. At the beginning of 1947 there were 57 families in the area, and by the end of the year there were 343.