Lamb was the son of Elizabeth Field and John Lamb. Lamb was the youngest child, with an 11 year older sister Mary, an even older brother John, and 4 other siblings that did not survive their infancy. John Lamb (father), who was a lawyer's clerk, spent most of his professional life as the assistant and servant to a barrister by the name of Samuel Salt who lived in the Inner Temple in London. It was there in the Inner Temple in Crown Office Row, that Charles Lamb was born and spent his youth. Lamb created a portrait of his father in his "Elia on the Old Benchers" under the name Lovel. Lamb's older brother was too much his senior to be a youthful companion to the boy but his sister Mary, being born eleven years before him, was probably his closest playmate. Lamb was also cared for by his paternal aunt Hetty, who seems to have had a particular fondness for him. A number of writings by both Charles and Mary suggest that the conflict between Aunt Hetty and her sister-in-law created a certain degree of tenseness in the Lamb household. However, Charles speaks fondly of her and her presence in the house seems to have brought a great deal of comfort to him.

Some of Lamb's fondest childhood memories were spent with Mrs. Field, his maternal grandmother, who was for many years a servant to the Plummer family, who owned a large country home called Blakesware House. After the death of Mrs. Plummer, Lamb's grandmother was in sole charge of the large home and, as Mr. Plummer was often absent, Charles had free rein of the place during his visits. A picture of these visits can be glimpsed in the Elia essay Blakesmoor in H...shire.

Little is known about Charles's life before the age of seven. We know that Mary taught him to read at a very early age and he read voraciously. It is believed that he suffered from smallpox during his early years which forced him into a long period of convalescence. After this period of recovery Lamb began to take lessons from Mrs. Reynolds, a woman who lived in the Temple and is believed to have been the former wife of a lawyer. Mrs. Reynolds must have been a sympathetic schoolmistress because Lamb maintained a relationship with her throughout his life and she is known to have attended dinner parties held by Mary and Charles in the 1820s. E.V. Lucas suggests that sometime in 1781 Charles left Mrs. Reynolds and began to study at the Academy of William Bird.

His time with William Bird did not last long, however, because by October 1782 Lamb was enrolled in Christ's Hospital, a charity boarding school chartered by King Edward VI in 1552. Christ's Hospital was a traditional English boarding school; bleak and full of violence. The headmaster, Mr. Boyer, has become famous for his teaching in Latin and Greek, but also for his brutality. A thorough record of Christ's Hospital in Several essays by Lamb as well as the Autobiography of Leigh Hunt and the Biographia Literaria of Samuel Taylor Coleridge, with whom Charles developed a friendship that would last for their entire lives. Despite the brutality Lamb got along well at Christ's Hospital, due in part, perhaps, to the fact that his home was not far distant thus enabling him, unlike many other boys, to return often to the safety of home. Years later, in his essay "Christ’s Hospital Five and Thirty Years Ago," Lamb described these events, speaking of himself in the third person as "L."

Christ's Hospital was a typical English boarding school and many students later wrote of the terrible violence they suffered there. The upper master of the school from 1778 to 1799 was Reverend James Boyer, a man renowned for his unpredictable and capricious temper. In one famous story Boyer was said to have knocked one of Leigh Hunt's teeth out by throwing a copy of Homer at him from across the room. Lamb seemed to have escaped much of this brutality, in part because of his amiable personality and in part because Samuel Salt, his father's employer and Lamb's sponsor at the school was one of the institute's Governors.

Charles Lamb suffered from a stutter and this "an inconquerable impediment" in his speech deprived him of Grecian status at Christ's Hospital and thus disqualifying him for a clerical career. While Coleridge and other scholarly boys were able to go on to Cambridge, Lamb left school at fourteen and was forced to find a more prosaic career. For a short time he worked in the office of Joseph Paice, a London merchant and then, for 23 weeks, until 8 February 1792, held a small post in the Examiner's Office of the South Sea House. Its subsequent downfall in a pyramid scheme after Lamb left would be contrasted to the company's prosperity in the first Elia essay. On 5 April 1792 he went to work in the Accountant's Office for British East India Company, the death of his father's employer having ruined the family's fortunes.Charles would continue to work there for 25 years, until his retirement with pension.

In 1792 while tending to his grandmother, Mary Field, in Hertfordshire, Charles Lamb fell in love with a young woman named Ann Simmons. Although no epistolary record exists of the relationship between the two, Lamb seems to have spent years wooing Miss Simmons. The record of the love exists in several accounts of Lamb's writing. Rosamund Gray is a story of a young man named Allen Clare who loves Rosamund Gray but their relationship comes to nothing because of the sudden death of Miss Gray. Miss Simmons also appears in several Elia essays under the name "Alice M." The essays "Dream Children," "New Year's Eve," and several others, speak of the many years that Lamb spent pursuing his love that ultimately failed. Miss Simmons eventually went on to marry a silversmith by the name of Bartram and Lamb called the failure of the affair his 'great disappointment.'

Charles and his sister Mary both suffered periods of mental illness. Charles spent six weeks in a psychiatric hospital during 1795. He was, however, already making his name as a poet.

On 22 September 1796, a terrible event occurred: Mary, "worn down to a state of extreme nervous misery by attention to needlework by day and to her mother at night," was seized with acute mania and stabbed her mother to the heart with a table knife.

Although there was no legal status of 'insanity' at the time, a jury returned a verdict of 'Lunacy' and therefore freed her from guilt of willful murder. With the help of friends Lamb succeeded in obtaining his sister's release from what would otherwise have been lifelong imprisonment, on the condition that he take personal responsibility for her safekeeping. Lamb used a large part of his relatively meagre income to keep his beloved sister in a private 'madhouse' in Islington called Fisher House.

The 1799 death of John Lamb was something of a relief to Charles because his father had been mentally incapacitated for a number of years since suffering a stroke. The death of his father also meant that Mary could come to live again with him in Pentonville, and in 1800 they set up a shared home at Mitre Court Buildings in the Temple, where they lived until 1809.

Despite Lamb's bouts of melancholia and alcoholism, both he and his sister enjoyed an active and rich social life. Their London quarters became a kind of weekly salon for many of the most outstanding theatrical and literary figures of the day. Charles Lamb, having been to school with Samuel Coleridge, counted Coleridge as perhaps his closest, and certainly his oldest, friend. On his deathbed, Coleridge had a mourning ring sent to Lamb and his sister. Fortuitously, Lamb's first publication was in 1796, when four sonnets by "Mr. Charles Lamb of the India House" appeared in Coleridge's Poems on Various Subjects. In 1797 he contributed additional blank verse to the second edition, and met the Wordsworths, William and Dorothy, on his short summer holiday with Coleridge at Nether Stowey, thereby also striking up a lifelong friendship with William. In London, Lamb became familiar with a group of young writers who favoured political reform, including Percy Bysshe Shelley, William Hazlitt, and Leigh Hunt.

Lamb continued to clerk for the East India Company and doubled as a writer in various genres, his tragedy, John Woodvil, being published in 1802. His farce, Mr H, was performed at Drury Lane in 1807, where it was roundly booed. In the same year, Tales from Shakespeare (Charles handled the tragedies; his sister Mary, the comedies) was published, and became a best seller for William Godwin's "Children's Library."

In 1819, at age 44, Lamb, who, because of family commitments, had never married, fell in love with an actress, Fanny Kelly, of Covent Garden, and proposed marriage. She refused him, and he died a bachelor. His collected essays, under the title Essays of Elia, were published in 1823 ("Elia" being the pen name Lamb used as a contributor to the London Magazine). A further collection was published ten years or so later, shortly before Lamb's death. He died of a streptococcal infection, erysipelas, contracted from a minor graze on his face sustained after slipping in the street, on 27 December 1834, just a few months after Coleridge. He was 59. From 1833 till their deaths Charles and Mary lived at Bay Cottage, Church Street, Edmonton north of London (now part of the London Borough of Enfield. Lamb is buried in All Saints' Churchyard, Edmonton. His sister, who was ten years his senior, survived him for more than a dozen years. She is buried beside him.

Lamb's first publication was the inclusion of four sonnets in the Coleridge's Poems on Various Subjects published in 1796 by Joseph Cottle. The sonnets were significantly influenced by the poems of Burns and the sonnets of William Bowles, a largely forgotten poet of the late 18th century. His poems garnered little attention and are seldom read today. Lamb's contributions to the second edition of the Poems showed significant growth as a poet. These poems included The Tomb of Douglas and A Vision of Repentance. Because of a temporary fall-out with Coleridge, Lamb's poems were to be excluded in the third edition of the Poems. As it turned out, a third edition never emerged and instead Coleridge's next publication was the monumentally influential Lyrical Ballads co-published with Wordsworth. Lamb, on the other hand, published a book entitled Blank Verse with Charles Lloyd, the mentally unstable son of the founder of Lloyd's Bank. Lamb's most famous poem was written at this time entitled The Old Familiar Faces. Like most of Lamb's poems it is particularly sentimental but it is still remembered and widely read, often included in Poetic Collections. Of particular interest to Lambarians is the opening verse of the original version of The Old Familiar Faces which is concerned with Lamb's mother. It was a verse that Lamb chose to remove from the edition of his Collected Work published in 1818.

From a fairly young age Lamb desired to be a poet but never gained the success that he had hoped. Lamb lived under the poetic shadow of his friend Coleridge. In the final years of the 18th century Lamb began to work on prose with the novella entitled Rosamund Gray, a story of a young girl that was thought to be inspired by Ann Simmonds, a girl that Charles Lamb was thought to be in love with. Although the story is not particularly successful as a narrative because of Lamb's poor sense of plot, it was well thought of by Lamb's contemporaries and led Shelley to observe “what a lovely thing is Rosamund Gray! How much knowledge of the sweetest part of our nature in it!" (Quoted in Barnett, page 50)

In the first years of the 19th century Lamb began his fruitful literary cooperation with his sister Mary. Together they wrote at least three books for William Godwin’s Juvenile Library. The most successful of these was of course Tales From Shakespeare which ran through two editions for Godwin and has now been published dozens of time in countless editions, many of them illustrated. Lamb also contributed a footnote to Shakespearean studies at this time with his essay "On the Tragedies of Shakespeare," in which he argues that Shakespeare should be read rather than performed in order gain the proper effect of his dramatic genius. Beside contributing to Shakespeare studies with his book Tales From Shakespeare, Lamb also contributed to the popularization of Shakespeare's contemporaries with his book Specimens of the English Dramatic Poets Who Lived About the TIme of Shakespeare.

Although he did not write his first Elia essay until 1820, Lamb’s gradual perfection of the essay form for which he eventually became famous began as early 1802 in a series of open letters to Leigh Hunt’s Reflector. The most famous of these is called "The Londoner" in which Lamb famously derides the contemporary fascination with nature and the countryside.