Henrietta Montalba was born in 1856, the youngest of four daughters of Anthony Rubens Montalba and Emeline (née Davies), all of whom would attain considerable success as artists. She was born in London. The 1871 British census shows Anthony Montalba living at 19 Arundel Gardens, Notting Hill, London, with four daughters, all artists. Montalba studied first at what was to become the Royal College of Art in South Kensington, and then in the Accademia di Belle Arti at Venice. Later she became a pupil of Jules Dalou, the French sculptor, during his residence in London.
Montalba first exhibited at the Royal Academy in 1876, and her work was often seen at the Grosvenor Gallery, the New Gallery, and elsewhere.
She mainly devoted herself to portrait or fancy busts; some executed in marble, like those of Doctor Mezger of Amsterdam (Grosvenor Gallery, 1886), and Dr. Schollander, the Scandinavian artist; others in bronze, like that of the Marquess of Lorne; but the greater part of her work was executed in terra cotta, as in the case of her bust of Robert Browning (Grosvenor Gallery, 1883). Other works worthy of note were "A Dalecarlian Peasant Woman" and "The Raven," representing a raven seated on a bust of Pallas, from the poem by Edgar Allan Poe. Her last work was of a more ambitious nature, being a life-size figure of "A Venetian Boy Catching a Crab," executed in bronze, which was exhibited at the Royal Academy in 1893, and at the World's Columbian Exposition, Chicago, in the same year. Her bronze bust of Richard Burchett, headmaster of the South Kensington Schools, has been transferred to the new building of the Royal Academy of Art, along with its setting designed by George Clausen.
She was on terms of friendship with her fellow-student Princess Louise, Duchess of Argyll, who painted a portrait of her and presented it to the Canadian Academy of Arts in Ottawa (now in the collection of the National Gallery of Canada). Both Henrietta and her sister Clara spent time with the Princess in Canada, painting landscapes.
Montalba was rarely separated from her family, residing in later days chiefly at Venice, Italy, and making frequent visits with them in Italy, Sweden, and elsewhere. Besides her artistic gifts she possessed great linguistic talent.
In 1892 her health began to fail her, and after a lingering illness she died in Venice, on September 14, 1893, and was buried near her father in the cemetery of San Michele.
One of her sculptures, a bronze titled Boy Catching a Crab, is displayed in The Victoria and Albert Museum. Her bronze bust of her principal at college, the heavily-bearded painter Richard Burchett, set in an elaborate bronze memorial frame designed by George Clausen, has followed the Royal College of Art to its new Darwin Building on Kensington Gore, where it is installed in a courtyard.