Colwyn Iestyn John Philipps, 3rd Viscount St Davids (30 January 1939 – 26 April 2009) was a British businessman, Conservative politician and writer on music. Besides his viscountcy, he also held the older titles of Baron Strange of Knockin (1299), Baron Hungerford (1426), and Baron de Moleyns (1445), & the Baronetcy of Picton Castle (1621). He was also a co-heir to the barony of Grey de Ruthyn.