Baron Trevor is a title that has been created three times. It was created first in 1662 in the Peerage of Ireland along with the viscountcy of Dungannon. For information on this creation, which became extinct in 1706, see Viscount Dungannon. The title was next created in the Peerage of Great Britain in 1712 for the lawyer Sir Thomas Trevor; the fourth Baron was created Viscount Hampden in 1776. Both titles became extinct in 1824 (see Viscount Hampden for more information). The family estate is Brynkinallt (Welsh: Bryncunallt), near Chirk, Denbighshire, in Wales.