Charles William Donaldson (4 January 1935 – 22 June 2005) was an English satirist, writer, playboy and, under the pseudonym of Henry Root, author of The Henry Root Letters.
Donaldson enjoyed a privileged upbringing in Sunningdale, Berkshire, as the son of a shipping magnate. He was educated at Winchester College, where he met Julian Mitchell. He spent some money supporting young writers such as his contemporaries Ted Hughes and Sylvia Plath. He completed his National Service in the Royal Navy in the late 1950s, reaching the rank of Sub-Lieutenant.
On his return to civilian life, Donaldson became associated with the set surrounding Princess Margaret, Countess of Snowdon, and worked as a theatrical producer. He established himself as a central player in the British satire boom of the early 1960s, as co-producer, with Donald Albery, of Beyond the Fringe (1960), and of dramatisations of J. P. Donleavy's The Ginger Man (1959) and Spike Milligan's The Bed-Sitting Room (1963). The pair earned a weekly £2,000 from Beyond the Fringe while the performers Peter Cook, Dudley Moore, Alan Bennett and Jonathan Miller were earning only £75.