Ralph Boteler, 1st Baron Sudeley and 6th Baron Sudeley KG (c. 1394 – 2 May 1473) was an English baron and aristocrat. He was the Captain of Calais and Treasurer of England (from 7 July 1443).
Ralph Boteler was the youngest surviving son of Thomas Boteler of Sudeley Castle, Gloucestershire and Alice Beauchamp (d. 1443), daughter of Sir John Beauchamp of Powick, Worcestershire.
Sudeley married twice. About 1418 he married commercial wealth, in the person of Elizabeth, widow of John Hende (d. 1418), late Mayor of London. She died in 1462, and in the following year he married Alice (d. 1474), daughter of John, Baron Deyncourt, and widow of William, Baron Lovel of Titchmarsh, Northamptonshire, who survived him.
The Boteler's elevation to the aristocracy arose from the marriage of Ralph's grandfather, William le Botiler of Wem to heiress Joan de Sudeley which led to his father succeeding to the title of Lord of Sudeley. The Barony of Sudeley was conferred upon him by Letters Patent. The title passed to both his elder brothers, John who died unmarried and childless in 1410 and William, who despite being married, also died childless seven years later. William's widow, Alice, was appointed governess of Henry VI in 1424.
He is thought to have served with King Henry V of England in France as he was awarded grants of land there in 1420-21. He was captain of Arques and Crotoy in 1423 and took muster in Calais in 1425. He served as Lord High Treasurer of England from 1443 to 1446.
Along with the title, Ralph inherited Sudeley Castle, which he rebuilt in the 1440s. Unfortunately he failed to gain royal permission to crenellate it and had to seek Henry VI's pardon. He lost it in 1469 due to his support for the Lancastrian cause.