The Four Stages of Cruelty is a series of four printed engravings published by English artist William Hogarth in 1751. Each print depicts a different stage in the life of the fictional Tom Nero.

Beginning with the torture of a dog as a child in the First stage of cruelty, Nero progresses to beating his horse as a man in the Second stage of cruelty, and then to robbery, seduction, and murder in Cruelty in perfection. Finally, in The reward of cruelty, he receives what Hogarth warns is the inevitable fate of those who start down the path Nero has followed: his body is taken from the gallows after his execution as a murderer and is mutilated by surgeons in the anatomical theatre.

The prints were intended as a form of moral instruction; Hogarth was dismayed by the routine acts of cruelty he witnessed on the streets of London. Issued on cheap paper, the prints were destined for the lower classes. The series shows a roughness of execution and a brutality that is untempered by the funny touches common in Hogarth's other works, but which he felt was necessary to impress his message on the intended audience. Nevertheless, the pictures still carry the wealth of detail and subtle references that are characteristic of Hogarth.

In common with other prints by Hogarth, such as Beer Street and Gin Lane, The Four Stages of Cruelty was issued as a warning against immoral behaviour, showing the easy path from childish thug to convicted criminal. His aim was to correct "that barbarous treatment of animals, the very sight of which renders the streets of our metropolis so distressing to every feeling mind". Hogarth loved animals, picturing himself with his pug in a self-portrait, and marking the graves of his dogs and birds at his home in Chiswick.

Hogarth deliberately portrayed the subjects of the engravings with little subtlety since he meant the prints to be understood by "men of the lowest rank" when seen on the walls of workshops or taverns. The images themselves, as with Beer Street and Gin Lane, were roughly drawn, lacking the finer lines of some of his other works. Fine engraving and delicate artwork would have rendered the prints too expensive for the intended audience, and Hogarth also believed a bold stroke could portray the passions of the subjects just as well as fine lines, noting that "neither great correctness of drawing or fine engraving were at all necessary".

To ensure that the prints were priced within reach of the intended audience, Hogarth originally commissioned the block-cutter J. Bell to produce the four designs as woodcuts. This proved more expensive than expected, so only the last two of the four images were cut and were not issued commercially at the time. Instead, Hogarth proceeded to create the engravings himself and announced the publication of the prints, along with that of Beer Street and Gin Lane, in the London Evening Post over three days from 14 to 16 February 1751. The prints themselves were published on 21 February 1751 and each was accompanied by a moralising commentary, written by the Rev. James Townley, a friend of Hogarth's. As with earlier engravings, such as Industry and Idleness, individual prints were sold on "ordinary" paper for 1s. (one shilling, equating to about £ 9.90 in 2023 terms), cheap enough to be purchased by the lower classes as a means of moral instruction. "Fine" versions were also available on "superior" paper for 1s. 6d. (one shilling and sixpence, about £ 14.90 in 2023 terms) for collectors.

Variations on plates III and IV exist from Bell's original woodcuts, bearing the earlier date of 1 January 1750, and were reprinted in 1790 by John Boydell, but examples from either of the woodcut printings are uncommon.

In the first print Hogarth introduces Tom Nero, whose surname may have been inspired by the Roman Emperor of the same name or a contraction of "No hero". Conspicuous in the centre of the plate, he is shown being assisted by other boys to insert an arrow into a dog's rectum, a torture apparently inspired by a devil punishing a sinner in Jacques Callot's Temptation of St. Anthony. A badge initialled with "S:G", on the shoulder of his light-hued, ragged coat, shows him to be receiving welfare from the parish of St Giles, in accordance with the Poor Act 1697, which required all recipients of parish charity to wear a badge with the parish's initials on their right shoulder. Hogarth used this notorious slum area as the background for many of his works including Gin Lane and Noon, part of the Four Times of the Day series. A more tender-hearted boy, perhaps the dog's owner, pleads with Nero to stop tormenting the frightened animal, even offering food in an attempt to appease him. This boy supposedly represents the young George, Prince of Wales (later King George III), who was twelve years old in the year the cartoon was published. His appearance is deliberately more pleasing than the scowling ugly ruffians that populate the rest of the picture, made clear in the text at the bottom of the scene:

While various Scenes of sportive Woe, The Infant Race employ, And tortur'd Victims bleeding shew, The Tyrant in the Boy.

Behold! a Youth of gentler Heart, To spare the Creature's pain, O take, he cries—take all my Tart, But Tears and Tart are vain.

Learn from this fair Example—You Whom savage Sports delight, How Cruelty disgusts the view, While Pity charms the sight.

The other boys carry out equally barbaric acts: the two boys at the top of the steps are burning the eyes out of a bird with a hot needle heated by the link-boy's torch; the boys in the foreground are throwing at a cock (perhaps an allusion to a nationalistic enmity towards the French, and a suggestion that the action takes place on Shrove Tuesday, the traditional day for cock-shying); another boy ties a bone to a dog's tail—tempting, but out of reach; a pair of fighting cats are hung by their tails and taunted by a jeering group of boys; in the bottom left-hand corner a dog is set on a cat, with the latter's intestines spilling out onto the ground; and in the rear of the picture another cat tied to two bladders is thrown from a high window. In a foreshadowing of his ultimate fate, Tom Nero's name is written under the chalk drawing of a man hanging from the gallows; the meaning is made clear by the schoolboy artist pointing towards Tom. The absence of parish officers who should be controlling the boys is an intentional rebuke on Hogarth's part; he agreed with Henry Fielding that one of the causes for the rising crime rate was the lack of care from the overseers of the poor, who were too often interested in the posts only for the social status and monetary rewards they could bring.

Below the text the authorship is established: Designed by W. Hogarth, Published according to Act of Parliament. 1 Feb.. 1751 The Act of Parliament referred to is the Engraving Copyright Act 1734. Many of Hogarth's earlier works had been reproduced in great numbers without his authority or any payment of royalties, and he was keen to protect his artistic property, so had encouraged his friends in Parliament to pass a law to protect the rights of engravers. Hogarth had been so instrumental in pushing the Bill through Parliament that on passing it became known as the "Hogarth Act".

In the second plate, the scene is Thavies Inn Gate (sometimes ironically written as Thieves Inn Gate), one of the Inns of Chancery which housed associations of lawyers in London. Tom Nero has grown up and become a hackney coachman, and the recreational cruelty of the schoolboy has turned into the professional cruelty of a man at work. Tom's horse, worn out from years of mistreatment and overloading, has collapsed, breaking its leg and upsetting the carriage. Disregarding the animal's pain, Tom has beaten it so furiously that he has put its eye out. In a satirical aside, Hogarth shows four corpulent barristers struggling to climb out of the carriage in a ludicrous state. They are probably caricatures of eminent jurists, but Hogarth did not reveal the subjects' names, and they have not been identified. Elsewhere in the scene, other acts of cruelty against animals take place: a drover beats a lamb to death, an ass is driven on by force despite being overloaded, and an enraged bull tosses one of its tormentors. Some of these acts are recounted in the moral accompanying the print:

The generous Steed in hoary Age, Subdu'd by Labour lies; And mourns a cruel Master's rage, While Nature Strength denies.

The tender Lamb o'er drove and faint, Amidst expiring Throws; Bleats forth it's innocent complaint And dies beneath the Blows.

Inhuman Wretch! say whence proceeds This coward Cruelty? What Int'rest springs from barb'rous deeds? What Joy from Misery?