Philip Sidney, 2nd Baron De L'Isle and Dudley (28 January 1828 – 17 February 1898), was an English hereditary peer.

He was the youngest child and only son born to Philip Sidney, 1st Baron De L'Isle and Dudley, and his wife, the former Lady Sophia FitzClarence.

His father was the only son of Sir John Shelley-Sidney, 1st Baronet, and Henrietta Hunloke, and was a first cousin of poet Percy Bysshe Shelley.

Upon his marriage to Mary, he assumed the additional name of Foulis after that of Sidney by Royal Warrant on 6 June 1850, under the will of his father-in-law, but relinquished it after her death in 1891.

[6] Lord De L'Isle and Dudley died at Westminster, London, on 17 February 1898 and was buried at Penshurst.