Cecil de Cardonnel, 2nd Baroness Dynevor (July 1735 – 14 March 1793) was a Welsh peeress.

Her mother was the daughter and heir of Adam de Cardonnel, British Secretary of War.

Rice was a Member of Parliament for county Carmarthenshire between 1754 and 1779 and Lord Lieutenant of Carmarthen from 1755 to 1779.

The widowed Lady Dinevor, took, by royal licence, the surname of de Cardonnel from 21 May 1787.

The title passed to her elder son, George Talbot-Rice who become the 3rd Baron Dynevor, resuming his paternal surname of Rice in 1827.