Arcielda Candiano (fl. c. 927 - 959) was a Dogaressa of Venice by marriage to the Doge Pietro III Candiano (r. 942 - 959). Her name is sometimes given as Richielda.
She was possibly the child of a Venetian and one of the Slav women who were brought to Venice as captives after the campaign against the Narentian pirates in the Adriatic in 887, before she married Pietro III Candiano. With the death of her husband in 959, Arcielda retired to become a nun as was by that time the custom for widowed dogaressas, though she inherited, through the terms of Pietro's will, a vineyard and other property in the marchese of Veneto, which she gave to the nuns of San Zaccaria.
Her two sons were Doge Pietro IV Candiano (930 - 976) and Domenigo Candiano, Bishop of Torcello. Her daughter Elena Candiano and her future husband Gerardo Guoro were the original persons upon whom the English dramatist William Shakespeare based his story Romeo and Juliet.