Walter Rice Howell Powell (1819 - 26 June 1889) was a Welsh landowner and Liberal politician. He was Member of Parliament for Carmarthenshire from 1880 until 1885 and for West Carmarthenshire from 1885 until his death in 1890.
Powell was the son of Walter Rice Howell Powell and his wife Mary Powell. He was educated at Christ Church, Oxford. On the death of his father in 1834 he inherited Maesgwynne estate of 3,468 acres (14.03 km2) in the parish of Llanboidy, Carmarthenshire, which had been owned by the Howell family.
Powell married Mary Anne, daughter of Henry Skrine, of Warleigh Manor, Somerset. They had one daughter. Following her death he married the daughter of Grismond Phillips of Cwmgwilly, and they also had a daughter who married W.F. Roch of Butter Hill, Pembrokeshire.
From an early age, Powell took an active interest in hunting, and is said to have spent much of his time at Oxford engaged in this pastime. For 50 years he was master of the foxhounds. He was a J.P. for Pembroke, Carmarthen and Cardiganshire and was High Sheriff of Carmarthenshire in 1849. In 1867 he funded a 24 piece brass band for Llanboidy.
He was responsible for building a new Market Hall in Llanboidy and also, during the 1870s, funded the restoration of the parish church.
Powell was engaged in public life from an early age and was High Sheriff of Carmarthenshire in 1840. For many years he supported the Conservative Party but, as was noted at the time of his death, he 'gave active support to men who could not be called genuine Conservatives, and he appears to have long cherished certain opinions of a democrative kind.' Chief amongst these was David Pugh, who represented Carmarthenshire in the House of Commons from 1857 until 1868. Pugh's political views were often described as vague and ambiguous, and for that reason he was placed at a disadvantage at the 1868 General Election when opposed by candidates who held pronounced Conservative and radical Liberal political views. Powell emerged as Pugh's leading supporter and public advocate during the 1868 election, and Pugh later followed Powell into the Liberal ranks.