The RAF ordered the Wessex HC.2 in Aug 1961 and used the HC.2 - 71 production airframes which could carry a 4000lb (1800 kg) slung load and 1 pre-production prototype. The first Wessex HC.2 was delivered in Feb 1963 and after trials, 18 Squadron used the first operational Wessex HC.2 on 9 Feb 1964. 72 Squadron replaced its Belvedere HC.1s with the Wessex HC.2 in Aug 1964, 78 Squadron re-equipped in 1965, followed by 240 Operational Conversion Unit in Jul 1967, 28 Squadron in Feb 1972, 103 Squadron in Nov 1972 and 84 Squadron in Mar 1982.
The RAF used two HCC.4 in the VVIP and VIP transport role between 1969 and 1998. More details under the Wessex HCC.4
Several former Royal Navy aircraft also listed here