William Cobbett was born in Farnham, Surrey, on 9 March 1763, the son of a tavern owner. He was taught to read and write by his father, and first worked as a farm labourer.

On 6 May 1783, on an impulse he took the stagecoach to London and spent eight or nine months as a clerk in the employ of a Mr Holland at Gray's Inn. He enlisted in the British Army in 1784, and made good use of the soldier's copious spare time to educate himself, particularly in English grammar. His regiment was posted to New Brunswick and he sailed from Gravesend to Halifax, Nova Scotia. Cobbett was in Saint John, Fredericton and elsewhere in the province until September 1791, rising through the ranks to become Sergeant Major, the most senior NCO.

He returned to England with his regiment, landing at Portsmouth 3 November 1791, and obtained discharge from the army on 19 December 1791. In Woolwich on 5 February 1792 he married Anne Reid, whom he had met while serving in Canada.

Cobbett had developed an animosity towards some corrupt officer, and he gathered evidence on the issue while in New Brunswick, but his charges against them were sidetracked. Sensing that he was about to be indicted in retribution he fled to France in March 1792 to avoid imprisonment. Cobbett had intended to stay a year to learn the French language but he found the French Revolution in full swing and the French Revolutionary Wars in progress, so he sailed for the United States in September 1792.

He was first at Wilmington, then Philadelphia by the Spring of 1793. Cobbett initially prospered by teaching English to Frenchmen and translating texts from French to English. He became a controversial political writer and pamphleteer, writing from a pro-British stance under the pseudonym Peter Porcupine.

A successful lawsuit brought against him by the eminent physician and politician Dr. Benjamin Rush, led to his fleeing to England in 1800 to avoid punishment. He sailed from New York, via Halifax, Nova Scotia to Falmouth in Cornwall.

Cobbett was greeted warmly by the British Establishment on arrival but refused all offers of reward for his propagandising in the United States.

Two years later he started his newspaper, the Weekly Political Register. At first he supported the Tories but he gradually became a radical. By 1806 he was a strong advocate of parliamentary reform.

He began publishing the Parliamentary Debates in 1802. This unofficial record of Parliamentary proceedings later became officially known as Hansard (see External link below).

Cobbett intented to stand for Parliament in Honiton in 1806, but was convinced by Thomas Cochrane, 10th Earl of Dundonald to let him stand in his stead. Both men campaigned together but were unsuccessful for they refused to bribe the voters by 'buying' votes; it also encouraged him in his opposition to rotten boroughs and the very urgent need for parliamentary reform.

Cobbett was found guilty of treasonous libel on 15 June 1810 after objecting in The Register to the flogging at Ely of local militiamen by Hanoverians. He was sentenced to two years imprisonment in infamous Newgate Prison. While in prison he wrote the pamphlet Paper against Gold, warning of the dangers of paper money, as well as many Essays and Letters. On his release a dinner in London, attended by 600 people, was given in his honour, presided over by Sir Francis Burdett who, like Cobbett, was a strong voice for parliamentary reform.

By 1815 the tax on newspapers had reached 4d. per copy. As few people could afford to pay 6d. or 7d. for a daily newspaper, the tax restricted the circulation of most of these journals to people with fairly high incomes. Cobbett was only able to sell just over a thousand copies a week. The following year Cobbett began publishing the Political Register as a pamphlet. Cobbett now sold the Political Register for only 2d. and it soon had a circulation of 40,000.

Cobbett's journal was the main newspaper read by the working class. This made Cobbett a dangerous man and in 1817 he learned that the government was planning to arrest him for sedition.

Following the passage of the Power of Imprisonment Bill in 1817, and fearing arrest for his arguably seditious writings, he fled to the United States. On Wednesday 27 March 1817 at Liverpool he embarked on board the ship Importer, D. Ogden master, bound for New York, accompanied by his two eldest sons, William and John Cobbett.

For two years Cobbett lived on a farm in Long Island where he wrote Grammar of the English Language and with the help of William Benbow, a friend in London, continued to publish the Political Register.

Cobbett also closely observed drinking habits in the United States. In 1819 he stated "Americans preserve their gravity and quietness and good-humour even in their drink." He believed it "far better for them to be as noisy and quarrelsome as the English drunkards; for then the odiousness of the vice would be more visible, and the vice itself might become less frequent."

A plan to return to England with the remains of the British radical pamphleteer, and revolutionary, Thomas Paine (died 1809) for a proper burial led to the ultimate loss of Paine's remains. The plan was to give Paine a heroic reburial on his native soil, but the bones were still among Cobbett's effects when he died over twenty years later. There is no confirmed story about what happened to them after that, although down the years various people have claimed to own parts of Paine's remains such as his skull and right hand.

Cobbett arrived back at Liverpool by ship in November 1819.

William Cobbett arrived back in England soon after the Peterloo Massacre. Cobbett joined with other Radicals in his attacks on the government and three times during the next couple of years was charged with libel.

In 1820 he stood for Parliament in Coventry but finished bottom of the poll.

Cobbett was not content to let the stories come to him, he went out like a modern reporter and dug them up, especially the story that he returned to time and time again in the course of his writings, the plight of the rural Englishman. He took to riding around the country on horseback making observations of what was happening in the towns and villages. Rural Rides, a work for which Cobbett is still known for today, first appeared in serial form in the Political Register running from 1822 to 1826. It was published in book form in 1830

While not a Catholic, Cobbett at this time also took up the cause of Catholic Emancipation. Between 1824 and 1826 he published his History of the Protestant Reformation, which challenged the traditional Protestant historical narrative of the British reformation, stressing the lengthy and often bloody persecutions of Catholics in Britain and Ireland. At this time Catholics were still forbidden to enter certain professions or to become Members of Parliament. Although the law was no longer enforced, it was officially still a crime to attend Mass or build a Catholic church.

In 1829, he published Advice to Young Men in which he heavily criticised An Essay on the Principle of Population published by the Reverend Thomas Robert Malthus.

Cobbett continued to publish controversial material in the Political Register and in July 1831, was charged with seditious libel after writing a pamphlet entitled Rural War in support of the Captain Swing Riots, which applauded those who were smashing farm machinery and burning haystacks. Cobbett conducted his own defence and he was so successful that the jury failed to convict him.

Cobbett still had a strong desire to be elected to the House of Commons. He was defeated in Preston in 1826 and Manchester in 1832 but after the passing of the 1832 Reform Act Cobbett was able to win the parliamentary seat of Oldham. In Parliament Cobbett concentrated his energies on attacking corruption in government and the 1834 Poor Law.

From 1831 until his death, he farmed at Normandy, a village in Surrey.

In his later life, however Macaulay, a fellow MP, remarked that his faculties were impaired by age; indeed that his paranoia had developed to the point of insanity.

He was a gifted writer, though later generations have taken offence at his some of his supposedly anti-Semitic and racist views. He is considered to have begun as an inherently conservative journalist who, angered by the corrupt British political establishment, became increasingly radical and sympathetic to anti-government ideals. He provides an alternative view of rural England in the age of an Industrial Revolution with which he was not in sympathy.

He was buried in the churchyard of St Andrew's Parish Church, Farnham.

In his lifetime Cobbett stood for parliament five times, four of which attempts were unsuccessful:

• 1806 Honiton
• 1820 Coventry
• 1826 Preston
• 1832 Manchester

In 1832 he was successful and elected as Member of Parliament for Oldham.

Cobbett's birthplace, a public house in Farnham named "The Jolly Farmer", has now been renamed "The William Cobbett".

The Brooklyn-based history band Piñataland has performed a song about William Cobbett's quest to rebury Thomas Paine entitled "American Man".

A story by Cobbett in 1807 led to the use of 'red herring' to mean a distraction from the important issue.

An equestrian statue of Cobbett is planned for a site in Farnham.

Cobbett's sons were trained as solicitors and founded a law firm in Manchester, still called Cobbetts in his honour.