[2] Its minimum width is 6 km (3.7 mi), between Wolstenholme Island and Cape Atholl, the mainland point at its southeastern end.

There is a tombolo named Uummannaq on the mainland shore at the eastern end of the sound by the former settlement of Pituffik.

[3] This strait was named after 17th-century English navigator Robert Bylot, who led two expeditions to find the Northwest Passage.

In the winter of 1849–1850 under Commander James Saunders of HMS North Star got frozen-in in the sound during an Arctic expedition to search and resupply Captain Sir James Clark Ross' venture, who in turn had sailed in 1848 trying to locate the whereabouts of Sir John Franklin's expedition.

[5] In 1968 a B-52 bomber carrying four thermonuclear bombs crashed in the ice of the Bylot Sound spreading contaminated material over the whole sector.