Lockwood de Forest II was born in New York in 1850, the son of Henry G. and Julia Weeks de Forest. The family were descendants of Jesse de Forest, a Huguenot exile who, in 1623, brought the first settlers from Holland to New Amsterdam. Encouraged by their parents, Lockwood and his three siblings were to develop lifelong interests in the arts. The eldest son, Robert Weeks {1848-1931}, became a lawyer and served as a trustee {and later president} of the Metropolitan Museum of Art in New York from 1889 until his death. Julia Brasher {1853-1910}, a devotee of painting and sculpture, wrote a book on the history of art and Henry Wheeler {1858-1938}, also a lawyer, was an avid art collector and amateur landscape architect.

Although he had begun to paint and draw somewhat earlier, it was during a visit to Rome in 1869 that the nineteen-year-old de Forest began to study art, taking painting lessons from the Italian landscapist Herman Corrodi. More important, it was on this same trip that Lockwood adopted American painter Frederic Edwin Church {1826-1900}, then on an extended stay abroad, as a mentor. According to de Forest, his affiliation with Church, a distant relation on his mother's side, was the strongest influence on his artistic maturation.

During his late twenties, following a pattern established in his childhood, de Forest made two extended sojourns abroad, in 1875-76 and 1877-78. These trips took him not only to the continental capitals but also the Middle East and North Africa. It was through browsing in Church's extensive library at Olana that de Forest's interest in the great art traditions of the East was kindled. From 1878 to about 1902, landscape painting was overshadowed by his activities centered around his preoccupation with the Indian architecture and Orientalist styled decor fashionable in late nineteenth century America. From 1879-83, de Forest, along with Louis Comfort Tiffany {founder of the American Arts & Crafts movement} was a partner in the interior decorating firm of Associated Artists. In 1879,de Forest married the former Meta Kemble, a grandaughter of Alfred V. du Pont, and visited India on his honeymoon, a nearly two year trip that he turned to his economic advantage, keeping his eyes peeled for objects and inspirations that would benefit Associated Artists. In Ahmadabad, he met Muggunbhai Hutheesing, a philanthropist whose woodcarving studio would become crucial to de Forest's career, partly to fill orders for his decorating firm, and also, to encourage continuance of the fast-disappearing Indian traditional handicrafts. Unlike European Orientalists, many of whom looked upon Asia and the Middle East with colonialist superiority, de Forest wanted to help the cause of Indian woodworkers and preserve traditional Indian arts and crafts. Part of him had a romantic response to the beauty, but he was pragmatic, too. Ms. Roberta Mayer, an art historian who has written a dissertation on de Forest says, "He wanted to make his art into a legitimate profession, a way to create beauty and make money at the same time". De Forest's work was exhibited at the Colonial and Indian Exhibition in London in 1886, and at the World's Columbian Exhibition seven years later, attracting an impressive array of clients: the steel king Andrew Carnegie, the transportation magnate Charles Tyson Yerkes, the hotelier Potter Palmer and even Mark Twain. De Forest was actively involved with the Indian workshop until after the turn of the century. In 1885 he had published a book on Indian architecture and in 1892-93 and in 1913 he made return trips to India.

Unfortunately the end of the nineteenth century brought with it the end of the Orientalist style in decor and de Forest's Indian experiment. By 1908, de Forest had sold his remaining stock of mouldings and furniture to his old friend Tiffany. De Forest again turned his attention to landscape painting and after beginning to winter in Santa Barbara, California sometime between 1889 and 1902 he eventually built a house there, settling permanently in 1922. De Forest did however, continue designing and decorating Indianate houses in the East, Midwest and West. His last and largest, the Dean's residence at Bryn Mawr College, was completed in 1919.

Lockwood de Forest II died in Santa Barbara in 1932.