Richard Child, 1st Earl Tylney (5 February 1680-March 1750), was an English Member of Parliament. He held no Office of State, nor any commercial directorship of significance, but is remembered chiefly as the builder of the now long-demolished Palladian "princely mansion"Wanstead House, one of the first in the style constructed in Britain. In the furnishing of his mansion Child became the main patron of the Flemish painter Old Nollekens. He died in March 1750 aged 70 at Aix-en-Provence, France, and was buried on 29 May 1750 at Wanstead.
Richard Child was baptised at Wanstead Church of the Virgin Mary on 5 February 1680, the third son of the wealthy Sir Josiah Child (1630–1699) Governor of the East India Company, who had been created 1st Baronet of Wanstead in 1678, by his third wife Emma Barnard (died 16 October 1725), daughter of Sir Henry Barnard, of Bridgnorth, Shropshire, Turkey merchant of London. He was appointed as residuary legatee and executor under the will of his father, whose death occurred before Richard's majority. Richard then on 12 February 1700 petitioned Parliament for a bill, to vest certain lands in trustees ,so that settlements made upon the marriage of his half-brother Josiah could be honoured.
In 1703 Richard married Dorothy Glynne, daughter and co-heiress of John Glynne, younger son of Sir John Glynne (died 1666), Lord Chief Justice, of Henley Park, Surrey, and Dorothy Tylney, daughter of Francis Tylney of Tylney Hall, Rotherwick, Hampshire. On 20 January 1704 he succeeded his half-brother Sir Josiah Child, 2nd Baronet, to the Baronetcy and to the Child manor of Wanstead, Essex, lying 6 miles north-east of the City of London. He also inherited a fortune of £4,000 per annum, which brought his total income to £10,000.
Following the first Baronets's death, his heir Josiah had leased Wanstead to his half-brother Richard. Coming into full possession of it, Sir Richard Child, 3rd Baronet, commissioned in 1715 the Scottish architect Colen Campbell to build a palatial Palladian mansion to replace the former manor house. By the time of its completion in 1722 Wanstead House had provided Child with a grand seat befitting his newly obtained status as Viscount Castlemaine, a creation of 1718.