Edward Estlin Cummings was born on October 14, 1894, in Cambridge, Massachusetts to Edward Cummings and the former Rebecca Haswell Clarke, a well-known Unitarian couple in the city. His father was a professor at Harvard University and later became nationally known as the minister of South Congregational Church in Boston, Massachusetts. His mother, who loved to spend time with her children, played games with Cummings and his sister, Elizabeth. From an early age, Cummings' parents supported his creative gifts. Cummings wrote poems and also drew as a child, and he often played outdoors with the many other children who lived in his neighborhood. He grew up in the company of such family friends as the Philosophers william James and Josiah Royce. Many of Cummings' summers were spent on Silver Lake in Madison, New Hampshire, where his father had built two houses along the eastern shore. The family ultimately purchased the nearby Joy Farm where Cummings had his primary summer residence.

Cummings wanted to be a poet from childhood and wrote poetry daily from age 8 to 22, exploring assorted forms. He graduated from Harvard University in 1915 and received an advanced degree from the university in 1916. In his studies at Harvard, he developed an interest in modern poetry, which ignored conventional grammar and syntax, while aiming for a dynamic use of language. Upon graduating, he worked for a book dealer.

They were imprisoned with other detainees in a large room. Cummings' father failed to obtain his son's release through diplomatic channels, and in December 1917 he wrote a letter to President Wilson. Cummings was released on December 19, 1917, and Brown was released two months later. Cummings used his prison experience as the basis for his novel, The Enormous Room (1922), about which F. Scott Fitzgerald said, "Of all the work by young men who have sprung up since 1920 one book survives—The Enormous Room by e e cummings... Those few who cause books to live have not been able to endure the thought of its mortality."

Cummings returned to the United States on New Year's Day 1918. Later in 1918 he was drafted into the army. He served in the 12th Division at Camp Devens, Massachusetts, until November 1918.

During the rest of the 1920s and 1930s, Cummings returned to Paris a number of times, and traveled throughout Europe, meeting, among others, Artist Pablo Picasso. In 1931 Cummings traveled to the Soviet Union, recounting his experiences in Eimi, published two years later. During these years Cummings also traveled to Northern Africa and Mexico. He worked as an Essayist and portrait Artist for Vanity Fair magazine (1924–1927).

Cummings returned to Paris in 1921 and had lived there for two years before returning to New York. His collection Tulips and Chimneys was published in 1923 and his inventive use of grammar and syntax is evident. The book was heavily cut by his Editor. XLI Poems was published in 1925. With these collections, Cummings made his reputation as an avant garde poet.

Following his autobiographical novel, The Enormous Room, Cummings' first published work was a collection of poems titled Tulips and Chimneys (1923). This work was the public's first encounter with his characteristic eccentric use of grammar and punctuation.

Cummings' first marriage, to Elaine Orr, began as a love affair in 1918 while she was still married to Scofield Thayer, one of Cummings' friends from Harvard. During this time he wrote a good deal of his erotic poetry. After divorcing Thayer, Elaine married Cummings on March 19, 1924. The couple had a daughter together out of wedlock. However, the couple separated after two months of marriage and divorced less than nine months later.

In 1926, Cummings' parents were in a car accident; only his mother survived, although she was severely injured. Cummings later described the accident in the following passage from his i: six nonlectures series given at Harvard (as part of the Charles Eliot Norton Lectures) in 1952 and 1953:

During his lifetime, Cummings published four plays. HIM, a three-act play, was first produced in 1928 by the Provincetown Players in New York City. The production was directed by James Light. The play's main characters are "Him", a Playwright, and "Me", his girlfriend.

Cummings married his second wife Anne Minnerly Barton on May 1, 1929, and they separated three years later in 1932. That same year, Anne obtained a Mexican divorce; it was not officially recognized in the United States until August 1934. Anne died in 1970 aged 72.

In the 1930s Samuel Aiwaz Jacobs was Cummings' publisher; he had started the Golden Eagle Press after working as a typographer and publisher.

According to his testimony in EIMI, Cummings had little interest in politics until his trip to the Soviet Union in 1931, after which he shifted rightward on many political and social issues. Despite his radical and bohemian public image, he was a Republican, and later, an ardent supporter of Joseph McCarthy.

Tom, A Ballet is a ballet based on Uncle Tom's Cabin. The ballet is detailed in a "synopsis" as well as descriptions of four "episodes", which were published by Cummings in 1935. It has never been performed.

In 1943, modern Dancer and Choreographer Jean Erdman presented "The Transformations of Medusa, Forever and Sunsmell" with a commissioned score by John Cage and a spoken text from the title poem by E. E. Cummings, sponsored by the Arts Club of Chicago. Erdman also choreographed "Twenty Poems" (1960), a cycle of E. E. Cummings' poems for eight Dancers and one actor, with a commissioned score by Teiji Ito. It was performed in the round at the Circle in the Square Theatre in Greenwich Village.

Santa Claus: A Morality was probably Cummings' most successful play. It is an allegorical Christmas fantasy presented in one act of five scenes. The play was inspired by his daughter Nancy, with whom he was reunited in 1946. It was first published in the Harvard College magazine, Wake. The play's main characters are Santa Claus, his family (Woman and Child), Death, and Mob. At the outset of the play, Santa Claus' family has disintegrated due to their lust for knowledge (Science). After a series of events, however, Santa Claus' faith in love and his rejection of the materialism and disappointment he associates with Science are reaffirmed, and he is reunited with Woman and Child.

He also sometimes included ethnic slurs in his writing. For instance, in his 1950 collection Xaipe: Seventy-One Poems, Cummings published two poems containing words that caused outrage in some quarters.

The use of lowercase for his initials was popularized in part by the title of some books, particularly in the 1960s, printing his name in lower case on the cover and spine. In the preface to E. E. Cummings: The Growth of a Writer by Norman Friedman, critic Harry T. Moore notes Cummings "had his name put legally into lower case, and in his later books the titles and his name were always in lower case." According to Cummings' widow, however, this is incorrect. She wrote to Friedman: "You should not have allowed H. Moore to make such a stupid & childish statement about Cummings & his signature." On February 27, 1951, Cummings wrote to his French translator D. Jon Grossman that he preferred the use of upper case for the particular edition they were working on. One Cummings scholar believes that on the rare occasions that Cummings signed his name in all lowercase, he may have intended it as a gesture of humility, not as an indication that it was the preferred orthography for others to use.

In 1952, his alma mater, Harvard University, awarded Cummings an honorary seat as a guest professor. The Charles Eliot Norton Lectures he gave in 1952 and 1955 were later collected as i: six nonlectures.

Cummings spent the last decade of his life traveling, fulfilling speaking engagements, and spending time at his summer home, Joy Farm, in Silver Lake, New Hampshire. He died of a stroke on September 3, 1962, at the age of 67 in North Conway, New Hampshire at the Memorial Hospital.

In 1934, after his separation from his second wife, Cummings met Marion Morehouse, a fashion model and Photographer. Although it is not clear whether the two were ever formally married, Morehouse lived with Cummings in a common-law marriage until his death in 1962. She died on May 18, 1969, while living at 4 Patchin Place, Greenwich Village, New York City, where Cummings had resided since September 1924.

He expressed transcendental leanings his entire life. As he matured, Cummings moved to an "I, Thou" relationship with God. His journals are replete with references to "le bon Dieu," as well as prayers for inspiration in his poetry and artwork (such as "Bon Dieu! may I some day do something truly great. amen."). Cummings "also prayed for strength to be his essential self ('may I be I is the only prayer—not may I be great or good or beautiful or wise or strong'), and for relief of spirit in times of depression ('almighty God! I thank thee for my soul; & may I never die spiritually into a mere mind through disease of loneliness')."