Rockwell Kent was born in Tarrytown, New York, the same year as fellow American artists George Bellows and Edward Hopper. Kent lived much of his early life in and around New York City, and moved in his mid 40s to an Adirondack farmstead that he called Asgaard where he lived and painted until his death. Kent studied with the influential painters and theorists of his day, including Arthur Wesley Dow, William Merritt Chase, Robert Henri, Abbott Thayer, and Kenneth Hayes Miller. An undergraduate background in architecture at Columbia University enabled Kent to work occasionally in the 1900s and 1910s as a draftsman and carpenter.

Kent's early paintings of Mount Monadnock and New Hampshire were first shown at the Society of American Artists in New York in 1904, when Dublin Pond was purchased by Smith College. In 1905 Kent ventured to Monhegan Island, Maine, where he based himself for the next five years. His first series of paintings of Monhegan were shown in 1907 at Clausen Galleries in New York to wide critical acclaim, and they form the foundation of his lasting reputation as an early American modernist. Among those lauding Kent was critic James Huneker of the Sun (who would soon deem the paintings of The Eight to be "decidedly reactionary"). Huneker praised Kent's brushwork as athletic and his colorful dissonances as daring. A transcendentalist and mystic in the tradition of Thoreau and Emerson whose works he read, Kent found inspiration in the austerity and stark beauty of wilderness. After Monhegan, he lived for extended periods of time in Newfoundland (1914 – 15), Alaska (1918 – 19), Tierra del Fuego (1922 – 23), Ireland (1926), and Greenland (1929; 1931 – 32; 1934 – 35).

In 1918-19 Kent and his nine year-old son ventured to the American frontier of Alaska. Wilderness (1920), the first of Kent's several adventure memoirs, is an edited and illustrated compilation of his letters home. Upon the artist's return to New York in 1919, publishing scion George Palmer Putnam and others, including Juliana Force — assistant to Gertrude Vanderbilt Whitney — implemented their avant-garde notion of incorporating the artist as "Rockwell Kent, Inc." to support him in his new Vermont homestead while he completed his paintings from Alaska for exhibition in 1920 at Knoedler Galleries in New York. Kent's small oil on wood panel sketches from Alaska — uniformly horizontal studies of light and color — were exhibited at Knoedler's as "Impressions." Their artistic lineage to the small and spare oil sketches of James Abbott McNeill Whistler (1834 – 1903), which are often entitled "Arrangements," underscores Kent's admiration of Whistler as a "genius."

Approached in 1926 by publisher R.R. Donnelley to produce an illustrated edition of Richard Henry Dana, Jr.'s Two Years Before the Mast, Kent suggested Moby Dick instead. Published in 1930 by the Lakeside Press of Chicago, the three volume limited edition filled with Kent's haunting black-and-white pen/brush and ink drawings sold out immediately; Random House produced a trade edition which was also immensely popular. A previously obscure book, Moby Dick had been rediscovered by critics in the early 1920s. The success of the Rockwell Kent illustrated edition was a factor in its becoming recognized as the classic it is today.

Less well known are Kent's talents as a jazz age humorist. As the gifted pen-and-ink draftsman "Hogarth, Jr.", Kent created a wealth of whimsical and irreverent drawings published by Vanity Fair, New York Tribune, Harper's Weekly, and the original Life. He brought his Hogarth, Jr. style to a series of richly colored reverse paintings on glass which he completed in 1918 and exhibited at Wanamaker's Department Store. (Two of these glass paintings are in the collection of the Columbus Museum of Art, part of the bequest of modernist collector Ferdinand Howald.) Further decorative work ensued intermittently: in 1939, Vernon Kilns reproduced three series of designs drawn by Kent (Moby Dick, Salamina, Our America) on its sets of contemporary china dinnerware.

Raymond Moore, founder and impresario of the Cape Playhouse and Cinema in Dennis MA, contracted with Rockwell Kent for the design of murals for the cinema, but the work of transferring and painting the designs on the 6,400-square-foot (590 m²) span was done by Kent's collaborator Jo Mielziner (1901 – 1976) and a crew of stage set painters from New York City. Ostensibly staying away from the state of Massachusetts to protest the Sacco and Vanzetti executions of 1927, Kent did in fact venture to Dennis in June 1930 to spend three days on the scaffolding, making suggestions and corrections. The signatures of both Kent and Mielziner appear on opposite walls of the cinema.

As World War II approached, Kent shifted his priorities, becoming increasingly active in progressive politics. In 1938 the U.S. Post Office asked him to paint a mural in their headquarters in Washington, DC; Kent included (in Inuit dialect and in tiny letters) a polemical statement in the painting, which caused some consternation. In 1939, he joined the Harlem Lodge of the International Workers Order (IWO), a Communist fraternal organization. A lithograph by Kent became the organization's logo in 1940, and, from 1944 to 1953, he served as the organization's President.

Increasingly supportive of Soviet-American friendship and a world devoid of nuclear weapons, Kent and his identity as an American painter receded in the postwar years; he became, along with hundreds of other prominent intellectuals and creative artists, a target of those in league with Joseph McCarthy. The rise of abstract expressionism cast a further shadow over Kent and others of his generation. In 1960 Kent donated several hundred of his paintings and drawings to the Soviet peoples and became an honorary member of the Soviet Academy of Fine Arts; he was awarded the Lenin Peace Prize in 1967. (Although many believe that Kent donated the prize money to the people of North Vietnam, an interview with Kent's wife Sally that appears in a 2006 documentary about his life states that he donated it to the women and children of Vietnam, both North and South.)

When Kent died, The New York Times described him as "... a thoughtful, troublesome, profoundly independent, odd and kind man who made an imperishable contribution to the art of bookmaking in the United States." This cursory summing-up of an American life has been superseded by richer, more accurate accounts of the scope of the artist's influential life as a painter and writer. Reappraisals of the artist's life and work have been mounted, most recently by the Portland (Maine) Museum of Art in the summer of 2005. Among the many notes of increased recognition is the appearance of one of Kent's pen-and-ink drawings from Moby Dick on a U.S. postage stamp, part of the 2001 commemorative panel celebrating American illustrators, including Maxfield Parrish, Frederic Remington, and Norman Rockwell.

The Archives of American Art is the repository for Kent's voluminous correspondence. Recently, prominent American and Canadian writers have found much gold to mine in Kent's improbable life of adventure and accomplishment. The year he spent in Newfoundland, for example, is fictionally (and very loosely) recalled by Canadian writer Michael Winter in The Big Why, his 2004 Winterset Award winning novel. And certain qualities of the protagonist of Russell Banks's 2008 novel The Reserve are inspired by aspects of Kent's complex personality.