Clara was born in Cheltenham on 2 August 1840, the eldest of the four daughters of the Swedish-born artist Anthony Rubens Montalba and Emeline (née Davies).
She and her three sisters (Ellen Emeline, Hilda Montalba, and Henrietta Mary Ann Skerrett) all attained high repute as artists.
[2] The 1871 British census shows Anthony Montalba living at 19 Arundel Gardens, Notting Hill, London, with four daughters, all artists.
Clara Montalba exhibited her work at the Palace of Fine Arts and The Woman's Building at the 1893 World's Columbian Exposition in Chicago, Illinois.
[2] Between 1879 and 1889 she exhibited her work at the Grosvenor Gallery, showing a series of scenes painted in Venice, which captured the unique mood and atmosphere of Venetian life.