Cape Breton Island is part of the province of Nova Scotia, Canada and site of the world famous Cabot Trail. The 10,311 km2 (3,981 sq mi) island accounts for 18.7% of the total area of Nova Scotia.

Although physically separated from the Nova Scotia peninsula by the Strait of Canso, it is artificially connected to mainland Nova Scotia by the 1,385 m (4,544 ft) long rock-fill Canso Causeway.

The island is located east-northeast of the mainland with its northern and western coasts fronting on the Gulf of Saint Lawrence. Its western coast also forms the eastern limits of the Northumberland Strait. The eastern and southern coasts front the Atlantic Ocean; its eastern coast also forming the western limits of the Cabot Strait.

Its landmass slopes upward from south to north, culminating in the Cape Breton Highlands in the northern part of the cape. One of the world's larger salt water lakes, Bras d'Or ("Arm of Gold" in French), dominates the centre of the island.

The turn of the 20th century saw Cape Breton Island at the forefront of scientific achievement with the now-famous activities launched by inventors Alexander Graham Bell and Guglielmo Marconi.

Following his successful invention of the telephone and being relatively wealthy, Bell acquired land near Baddeck in 1885, largely due to surroundings reminiscent of his early years in Scotland. He established a summer estate complete with research laboratories, working with deaf people?including Helen Keller?and continued to invent. Baddeck would be the site of his experiments with hydrofoil technologies as well as the Aerial Experiment Association, financed by his wife, which saw the first powered flight in the British Empire when the AEA Silver Dart took off from the ice-covered waters of Bras d'Or Lake. Bell also built the forerunner to the iron lung and he experimented with breeding sheep.

Marconi's contributions to Cape Breton Island were somewhat less than Bell's as he merely used the island's geography to his advantage in transmitting the first North American trans-Atlantic radio message from a station constructed at Table Head in Glace Bay to a receiving station at Poldhu in Cornwall, England.

Promotions for tourism beginning in the 1950s recognized the importance of the Scottish culture to the province, and the provincial government started encouraging the use of Gaelic once again. The establishment of funding for the Gaelic College of Celtic Arts and Crafts and formal Gaelic language courses in public schools are intended to address the near-loss of this culture to English assimilation.

In the 1960s, the Fortress of Louisbourg was partially reconstructed by Parks Canada. Today this National Historic Site of Canada is one of the island's dominant economic engines, employing many residents and attracting thousands of tourists every year. The Fortress has also led to the revial and pride of the Acadian community who were the first settlers along with the Mi'kmaq. Ile Madame and Ch?ticamp are well known for their hospitality and fine food.