Some of Elizabeth Barrett's family had lived in Jamaica since 1655. Their wealth derived mainly from Edward Barrett (1734–1798), owner of 10,000 acres (4,000 ha) in the estates of Cinnamon Hill, Cornwall, Cambridge and Oxford in northern Jamaica. Elizabeth's maternal grandfather owned sugar plantations, mills, glassworks and ships that traded between Jamaica and Newcastle. Biographer Julia Markus states the poet "believed that she had African blood through her grandfather Charles Moulton", but there is no evidence of this — although other branches of her family had African blood through relationships between plantation owners and slaves. What the family believed to be their genealogy in relation to Jamaica is unclear.

Elizabeth Barrett Moulton-Barrett was born on 6 March 1806, in Coxhoe Hall, between the villages of Coxhoe and Kelloe in County Durham, England. Her parents were Edward Barrett Moulton Barrett and Mary Graham Clarke; Elizabeth was the eldest of 12 children (eight boys and four girls). All lived to adulthood except for one girl, who died at the age of three, when Elizabeth was eight.

In 1809, the family moved to Hope End, a 500-acre (200 ha) estate near the Malvern Hills in Ledbury, Herefordshire. Her father converted the Georgian house into stables and built a new mansion of opulent Turkish design, which his wife described as something from the Arabian Nights Entertainments.

Barrett Browning's first known poem was written at the age of six or eight, "On the Cruelty of Forcement to Man". The manuscript, which protests against impressment, is currently in the Berg Collection of the New York Public Library; the exact date is controversial because the "2" in the date 1812 is written over something else that is scratched out.

In 1820 Mr Barrett privately published The Battle of Marathon, an epic-style poem, though all copies remained within the family. Her mother compiled the child's poetry into collections of "Poems by Elizabeth B. Barrett". Her father called her the "Poet Laureate of Hope End" and encouraged her work. The result is one of the largest collections of juvenilia of any English Writer. Mary Russell Mitford described the young Elizabeth at this time, as having "a slight, delicate figure, with a shower of dark curls falling on each side of a most expressive face; large, tender eyes, richly fringed by dark eyelashes, and a smile like a sunbeam."

Her first independent publication was "Stanzas Excited by Reflections on the Present State of Greece" in The New Monthly Magazine of May 1821; followed two months later by "Thoughts Awakened by Contemplating a Piece of the Palm which Grows on the Summit of the Acropolis at Athens".

Her first collection of poems, An Essay on Mind, with Other Poems, was published in 1826 and reflected her passion for Byron and Greek politics. Its publication drew the attention of a blind scholar of the Greek language, Hugh Stuart Boyd, and of another Greek scholar, Uvedale Price, with whom she maintained sustained correspondence. Among other neighbours was Mrs James Martin from Colwall, with whom she also corresponded throughout her life. Later, at Boyd's suggestion, she translated Aeschylus' Prometheus Bound (published in 1833; retranslated in 1850). During their friendship Barrett studied Greek literature, including Homer, Pindar and Aristophanes.

Elizabeth's mother died in 1828, and is buried at St Michael's Church, Ledbury, next to her daughter Mary. Sarah Graham-Clarke, Elizabeth's aunt, helped to care for the children, and she had clashes with Elizabeth's strong will. In 1831 Elizabeth's grandmother, Elizabeth Moulton, died. Following lawsuits and the abolition of slavery Mr Barrett incurred great financial and investment losses that forced him to sell Hope End. Although the family was never poor, the place was seized and put up for sale to satisfy creditors. Always secret in his financial dealings, he would not discuss his situation and the family was haunted by the idea that they might have to move to Jamaica.

In the 1830s Elizabeth was introduced to literary society through her cousin, John Kenyon. Her first adult collection of poems was published in 1838 and she wrote prolifically between 1841 and 1844, producing poetry, translation and prose. She campaigned for the abolition of slavery and her work helped influence reform in the child labour legislation. Her prolific output made her a rival to Tennyson as a candidate for poet laureate on the death of Wordsworth.

Elizabeth opposed slavery and published two poems highlighting the barbarity of slavers and her support for the abolitionist cause: "The Runaway Slave at Pilgrim's Point"; and "A Curse for a Nation". In "Runaway" she describes a slave woman who is whipped, raped, and made pregnant as she curses the slavers. Elizabeth declared herself glad that the slaves were "virtually free" when the Emancipation Act abolishing slavery in British colonies was passed in 1833, despite the fact that her father believed that Abolitionism would ruin his Business.

During 1837–38 the poet was struck with illness again, with symptoms today suggesting tuberculous ulceration of the lungs. That same year, at her physician's insistence, she moved from London to Torquay, on the Devonshire coast. Two tragedies then struck. In February 1840 her brother Samuel died of a fever in Jamaica. Then her favourite brother Edward ("Bro") was drowned in a sailing accident in Torquay in July. This had a serious effect on her already fragile health. She felt guilty as her father had disapproved of Edward's trip to Torquay. She wrote to Mitford, "That was a very near escape from madness, absolute hopeless madness". The family returned to Wimpole Street in 1841.

In 1838 The Seraphim and Other Poems appeared, the first volume of Elizabeth's mature poetry to appear under her own name.

Between 1841 and 1844 Barrett Browning was prolific in poetry, translation and prose. The poem "The Cry of the Children", published in 1842 in Blackwoods, condemned child labour and helped bring about child-labour reforms by raising support for Lord Shaftesbury's Ten Hours Bill (1844). At about the same time, she contributed critical prose pieces to Richard Henry Horne's A New Spirit of the Age.

In the correspondence Barrett Browning kept with the Reverend william Merry from 1843 to 1844 on predestination and salvation by works, she identifies herself as a Congregationalist: "I am not a Baptist — but a Congregational Christian, — in the holding of my private opinions."

Her 1844 volume Poems made her one of the most popular Writers in the country, and inspired Robert Browning to write to her. He wrote, "I love your verses with all my heart, dear Miss Barrett," praising their "fresh strange music, the affluent language, the exquisite pathos and true new brave thought."

Barrett Browning was widely popular in the United Kingdom and the United States during her lifetime. Edgar Allan Poe was inspired by her poem Lady Geraldine's Courtship and specifically borrowed the poem's metre for his poem The Raven. Poe had reviewed Barrett Browning's work in the January 1845 issue of the Broadway Journal, saying that "her poetic inspiration is the highest — we can conceive of nothing more august. Her sense of Art is pure in itself." In return, she praised The Raven, and Poe dedicated his 1845 collection The Raven and Other Poems to her, referring to her as "the noblest of her sex".

The courtship and marriage between Robert Browning and Elizabeth were carried out secretly, as she knew her father would disapprove. After a private marriage at St Marylebone Parish Church, they honeymooned in Paris before moving to Italy, in September 1846, which became their home almost continuously until her death. Elizabeth's loyal nurse, Wilson, who witnessed the marriage, accompanied the couple to Italy.

The couple came to know a wide circle of artists and Writers including william Makepeace Thackeray, Sculptor Harriet Hosmer (who, she wrote, seemed to be the "perfectly emancipated female") and Harriet Beecher Stowe. In 1849 she met Margaret Fuller, and the female French Novelist George Sand in 1852, whom she had long admired. Among her intimate friends in Florence was the Writer Isa Blagden, whom she encouraged to write novels. They met Alfred Tennyson in Paris, and John Forster, Samuel Rogers and the Carlyles in London, later befriending Charles Kingsley and John Ruskin.

Sonnets from the Portuguese was published in 1850. There is debate about the origin of the title. Some say it refers to the series of sonnets of the 16th-century Portuguese poet Luís de Camões. However, "my little Portuguese" was a pet name that Browning had adopted for Elizabeth and this may have some connection.

The date of publication of these poems is in dispute, but her position on slavery in the poems is clear and may have led to a rift between Elizabeth and her father. She wrote to John Ruskin in 1855 "I belong to a family of West Indian slaveholders, and if I believed in curses, I should be afraid". After the Jamaican slave uprising of 1831–32, her father and uncle continued to treat the slaves humanely.

The verse-novel Aurora Leigh, her most ambitious and perhaps the most popular of her longer poems, appeared in 1856. It is the story of a female Writer making her way in life, balancing work and love, and based on Elizabeth's own experiences. Aurora Leigh was an important influence on Susan B. Anthony's thinking about the traditional roles of women, with regard to marriage versus independent individuality. The North American Review praised Elizabeth's poem: "Mrs. Browning's poems are, in all respects, the utterance of a woman — of a woman of great learning, rich experience, and powerful genius, uniting to her woman's nature the strength which is sometimes thought peculiar to a man."

After the death of an old friend, G. B. Hunter, and then of her father, Barrett Browning's health started to deteriorate. The Brownings moved from Florence to Siena, residing at the Villa Alberti. Engrossed in Italian politics, she issued a small volume of political poems titled Poems before Congress (1860) "most of which were written to express her sympathy with the Italian cause after the outbreak of fighting in 1859". They caused a furore in England, and the conservative magazines Blackwood's and the Saturday Review labelled her a fanatic. She dedicated this book to her husband. Her last work was A Musical Instrument, published posthumously.

Barrett Browning's sister Henrietta died in November 1860. The couple spent the winter of 1860–61 in Rome where Barrett Browning's health further deteriorated and they returned to Florence in early June 1861. She became gradually weaker, using morphine to ease her pain. She died on 29 June 1861 in her husband's arms. Browning said that she died "smilingly, happily, and with a face like a girl's.... Her last word was... ''Beautiful". She was buried in the Protestant English Cemetery of Florence. "On Monday July 1 the shops in the area around Casa Guidi were closed, while Elizabeth was mourned with unusual demonstrations." The nature of her illness is still unclear. Some modern Scientists speculate her illness may have been hypokalemic periodic paralysis, a genetic disorder that causes weakness and many of the other symptoms she described.

In 1892, Ledbury, Herefordshire, held a design competition to build an Institute in honour of Barrett Browning. Brightwen Binyon beat 44 other designs. It was based on the timber-framed Market House, which was opposite the site. It was completed in 1896. However, Nikolaus Pevsner was not impressed by its style. In 1938, it became a public library. It has been Grade II-listed since 2007.

Lilian Whiting published a biography of Barrett Browning (1899) which describes her as "the most philosophical poet" and depicts her life as "a Gospel of applied Christianity". To Whiting, the term "art for art's sake" did not apply to Barrett Browning's work, as each poem, distinctively purposeful, was borne of a more "honest vision". In this critical analysis, Whiting portrays Barrett Browning as a poet who uses knowledge of Classical literature with an "intuitive gift of spiritual divination". In Elizabeth Barrett Browning, Angela Leighton suggests that the portrayal of Barrett Browning as the "pious iconography of womanhood" has distracted us from her poetic achievements. Leighton cites the 1931 play by Rudolf Besier, The Barretts of Wimpole Street, as evidence that 20th-century literary criticism of Barrett Browning's work has suffered more as a result of her popularity than poetic ineptitude. The play was popularized by Actress Katharine Cornell, for whom it became a signature role. It was an enormous success, both artistically and commercially, and was revived several times and adapted twice into movies.

At Wimpole Street Barrett Browning spent most of her time in her upstairs room. Her health began to improve, though she saw few people other than her immediate family. One of those was Kenyon, a wealthy friend of the family and patron of the arts. She received comfort from a spaniel named Flush, a gift from Mary Mitford. (Virginia Woolf later fictionalised the life of the dog, making him the protagonist of her 1933 novel Flush: A Biography).

Throughout the 20th century, literary criticism of Barrett Browning's poetry remained sparse until her poems were discovered by the women's movement. She once described herself as being inclined to reject several women's rights principles, suggesting in letters to Mary Russell Mitford and her husband that she believed that there was an inferiority of intellect in women. In Aurora Leigh, however, she created a strong and independent woman who embraces both work and love. Leighton writes that because Elizabeth participates in the literary world, where voice and diction are dominated by perceived masculine superiority, she "is defined only in mysterious opposition to everything that distinguishes the male subject who writes..." A five-volume scholarly edition of her works was published in 2010, the first in over a century.

Much of Barrett Browning's work carries a religious theme. She had read and studied such works as Milton's Paradise Lost and Dante's Inferno. She says in her writing, "We want the sense of the saturation of Christ's blood upon the souls of our poets, that it may cry through them in answer to the ceaseless wail of the Sphinx of our humanity, expounding agony into renovation. Something of this has been perceived in art when its glory was at the fullest. Something of a yearning after this may be seen among the Greek Christian poets, something which would have been much with a stronger faculty". She believed that "Christ's religion is essentially poetry — poetry glorified". She explored the religious aspect in many of her poems, especially in her early work, such as the sonnets.