Donoghue v Stevenson is a famous legal case in the field of tort law that established the modern concept of negligence in the law of England and Wales, and in other common law jurisdictions. The case was heard in the House of Lords, the highest court in the UK at the time, in 1932.

In this case, Mrs. Donoghue consumed a bottle of ginger beer that had been purchased for her by a friend in a café in Scotland. Unknown to her, the bottle contained the remains of a snail, and she became ill as a result. Mrs. Donoghue brought a claim against the manufacturer of the ginger beer, Mr. Stevenson, alleging that he owed her a duty of care as a consumer of his product, and that he had breached that duty by allowing a snail to enter the bottle.

The House of Lords ultimately ruled in favor of Mrs. Donoghue, establishing the concept of the “neighbour principle,” which holds that a person owes a duty of care to those who are so closely and directly affected by their actions that they ought to have them in contemplation as being so affected when they are directing their mind to the acts or omissions in question. This principle has become a cornerstone of negligence law, and has been applied in countless cases since Donoghue v Stevenson.