The title of Viscount Downe was created in the Peerage of Ireland in 1680. The Viscount bears the subsidiary title of Baron Dawnay (1897) in the Peerage of the United Kingdom, under which he sat in the House of Lords before 1999.

Viscounts Downe, First Creation (1675)

• William Ducie, 1st Viscount Downe (c. 1612-1679)

Viscounts Downe, Second Creation (1680)

• John Dawnay, 1st Viscount Downe (1625-1695)
• Henry Dawnay, 2nd Viscount Downe (1664-1741)
• Henry Pleydell Dawnay, 3rd Viscount Downe (1727_1760)
• John Dawnay, 4th Viscount Downe (1728-1780)
• John Christopher Burton Dawnay, 5th Viscount Downe (1764-1832)
• William Henry Dawnay, 6th Viscount Downe (1772_1846)
• William Henry Dawnay, 7th Viscount Downe (1812_1857)
• Hugh Richard Dawnay, 8th Viscount Downe (1844_1924)
• John Dawnay, 9th Viscount Downe (1872-1931)
• Richard Dawnay, 10th Viscount Downe (1903_1965)
• John Christian George Dawnay, 11th Viscount Downe (b. 1935)