Lily Delissa Joseph (née Leah Alice Solomon) was born into a Jewish family in Bermondsey, London, England on 24 June 1863, the younger sister of the artist Solomon J Solomon, who probably encouraged her to paint. She trained at the Ridley School of Art and the Royal Academy of Art, becoming a portrait, landscape and interior painter with a studio in Bedford Row overlooking the Old Bailey. She exhibited with the Society of Women Artists, the New English Art Club, the Women's International Art Club and at the Royal Academy (1905-38), as well as in the Paris Salons (where she won a silver medal in 1929 and a gold in 1934), and was later known for her experimentation and a limited palette of white, cobalt, rose madder, orange madder and black. Deeply involved in the women's suffrage movement, she was famously unable to attend her own Private View for her exhibition 'Some London and Country Interiors' at the Baillie Gallery, London in 1912 after being detained at Holloway Gaol 'on a charge in connection with [the] Women's Suffrage Movement'. One of the first women to own and drive a car, she also learnt to fly aeroplanes when in her fifties. A committed member of the Jewish community, she was involved in many charitable ventures. In 1911 she met the young poet Isaac Rosenberg while painting at the National Gallery (she depicted its interior in a number of works). She employed him briefly as a tutor to her children and her sister Mrs. Henrietta Lowy Solomon did the same, before introducing him to their wealthier friend Mrs Herbert Cohen, who sponsored his studies at the Slade School of Fine Art. She was also religiously observant and well-known for her musical voice in the communal singing at the Brook Green synagogue in Hammersmith (having also been active in its establishment).

In 1924 she married the architect Delissa Joseph, F.R.I.B.A. (1859–1927) and exhibited her paintings alongside his drawings at the Suffolk Street Galleries in the same year. Delissa Joseph built two of her brother Solomon's studios including one at Birchington in Kent, where both brother and sister painted studies of the interior. She outlived her husband by thirteen years and died in London, England on 24 July 1940. In 1946 Ben Uri held a joint exhibition of paintings by Solomon J. Solomon and Lily Delissa Joseph. Her work is represented in UK Collections including the Tate.