Edna St. Vincent Millay (February 22, 1892 – October 19, 1950) was a lyrical poet and playwright, and the second woman to receive the Pulitzer Prize for Poetry, after Sara Teasdale. She was also known for her unconventional, bohemian lifestyle and her many love affairs with men and women. She used the pseudonym Nancy Boyd for her prose work.

Millay was born in Rockland, Maine, to Cora Lounella (Buzzelle), a nurse, and Henry Tollman Millay, a schoolteacher who would later become superintendent of schools. Her middle name is derived from St. Vincent's Hospital in New York, where her uncle's life had beeen saved just prior to her birth.

In 1904, Cora officially divorced Millay's father for financial irresponsibility, but they had been separated for some years prior. Struggling financially, Cora and her three daughters, Edna (who would later insist on being called "Vincent"), Norma and Kathleen, moved from town to town, counting on the kindness of friends and relatives. Though poor, Cora never traveled without her trunk full of classic literature — including William Shakespeare, John Milton, and more — which she enthusiastically read to her children in her Irish brogue. Finally the family settled in Camden, Maine, moving into a small house on the property of Cora's well-heeled aunt. It was in this modest house in the middle of a field that Millay wrote the first of the poems that would catapult her to literary fame.

Cora taught her daughters to be independent and to speak their minds, which did not always sit well with the authority figures in Millay's life. Millay preferred to be called "Vincent" rather than Edna, which she found plain — her grade school principal, offended by her frank attitudes, refused to call her Vincent — instead, he called her by any woman's name that started with a V. ^

At Camden High School, Millay began nurturing her budding literary talents, starting at the school's literary magazine, The Megunticook, and eventually having some of her poetry published in the popular children's magazine St. Nicholas, the Camden Herald and, significantly, the anthology Current Literature, all by the age of 15.

Millay rose to fame with her poem "Renascence" (1912), and on the strength of it was awarded a scholarship to Vassar College. After her graduation in 1917, she moved to New York City.

In New York, she lived in Greenwich Village. It was at this time that she first attained great popularity in America. She won the Pulitzer Prize for Poetry in 1923, for The Harp-Weaver, and Other Poems. Her reputation was damaged by poetry she wrote in support of the Allied war effort during World War II. Merle Rubin noted: "She seems to have caught more flak from the literary critics for supporting democracy than Ezra Pound did for championing fascism."

Millay, a bisexual, had well-known affairs with other important women in the writing community, which were at times problematic. In late 1912 she spent time in Vienna, Austria and travelled through Italy and Albania. She later went to Paris, where she met novelist Djuna Barnes, with whom she had a strained romantic relationship. Their liaison was marred by mutual jealousy, partly due to a literary rivalry, but mostly because Millay also had an affair with Barnes' long time partner, sculptress Thelma Ellen Wood. Millay allowed her involvement with both Barnes and Wood to come to light, spawning a terrible fight between the three lovers. Both Barnes and Wood ended their relationships with Millay and remained together, but later separated after feuding about another woman. Millay also was involved for some time with the photographer Berenice Abbott, and had a short affair with writer Natalie Barney.

In 1923, she married Eugene Jan Boissevain, then the 43-year-old widower of labor lawyer and war correspondant Inez Milholland. Boissevain greatly supported her career and took primary care of domestic responsibilities. They lived in Austerlitz, New York, at a farmhouse they called Steepletop.

Millay's marriage with Boissevain was an open one. During this time, Millay took many male and female lovers, including the poet George Dillon, fourteen years her junior, for whom a number of her sonnets were written. Millay also collaborated with Dillon on Flowers of Evil, a translation of Charles Baudelaire's Les Fleurs du Mal.

Boissevain died in 1949 of lung cancer. Millay died about a year later of a heart attack. She was found dead at the bottom of the stairs in her house, a result of intoxication, a poem clutched in her hand.

My candle burns at both ends;

It will not last the night;

But ah, my foes, and oh, my friends--

It gives a lovely light!

Mathematicians recognize her poem "Euclid Alone Has Looked on Beauty Bare" (1923) as an expression of mathematical beauty, or an homage to the geometer Euclid.

However, many consider "Renascence" and "The Ballad Of The Harp-Weaver" to be her finest poems.

Thomas Hardy once said that America had two great attractions: the skyscraper and the poetry of Edna St. Vincent Millay.

• Epstein, Daniel Mark. (2001) What Lips my Lips Have Kissed: The Loves and Love Poems of Edna St. Vincent Millay. New York: Henry Holt. ISBN 0-8050-6727-2

• Works by Edna St. Vincent Millay at Project Gutenberg
• "Renascence" at Bartleby
• "The Ballad Of The Harp-Weaver" at A Celebration of Women Writers
• Biography of Millay
• Biography of Wood