The title of Earl Nelson of Trafalgar was created in 1805 for William Nelson, older brother of the late admiral Horatio Nelson, 1st Viscount Nelson.

The Earl bears the subsidiary titles of Viscount Merton of Trafalgar (1805) and Baron Nelson of the Nile and of Hillsborough (1801).

Barons Nelson of the Nile (1801)

• Horatio Nelson, 1st Viscount Nelson, 1st Baron Nelson of the Nile (1758-1805)
• William Nelson, 2nd Baron Nelson of the Nile (1757-1835) (became Earl Nelson in 1805)

Earls Nelson (1805)

• William Nelson, 1st Earl Nelson (1757-1835)
• Thomas Nelson, 2nd Earl Nelson (d. 1835)
• Horatio Nelson, 3rd Earl Nelson (d. 1913)
• Thomas Horatio Nelson, 4th Earl Nelson (d. 1947)
• Edward Agar Horatio Nelson, 5th Earl Nelson (d. 1951)
• Albert Francis Joseph Horatio Nelson, 6th Earl Nelson (d. 1957)
• Henry Edward Joseph Horatio Nelson, 7th Earl Nelson (d. 1972)
• George Joseph Horatio Nelson, 8th Earl Nelson (d. 1981)
• Peter John Horatio Nelson, 9th Earl Nelson (b. 1941)