Reading law was the primary method used in common law countries, particularly the United States, for people to prepare for and enter the legal profession before the advent of law schools. In Commonwealth countries, becoming an articled clerk was a similar practice.

It consisted of an extended internship or apprenticeship under the tutelage or mentoring of an experienced lawyer. The practice largely died out in the early 20th century. A few U.S. states, namely California, Maine, New York, Vermont, Virginia and Washington, still permit people to become lawyers by reading law instead of attending some or all of law school, although the practice is uncommon.

In this sense, "reading law" specifically refers to a means of entering the profession, although in England it is still customary to say that a university undergraduate is "reading" a course, which may be law or any other.

In colonial America, as in Britain in that day, law schools did not exist at all until Litchfield Law School was founded in 1773. Within a few years following the American Revolution, some universities such as the College of William and Mary and the University of Pennsylvania established a "Chair in Law". However, the holder of this position would be the sole purveyor of legal education for the institution, and would give lectures designed to supplement, rather than replace, an apprenticeship. Even as a handful of law schools were established, they remained uncommon in the United States until the late nineteenth century. Most people who entered the legal profession did so through an apprenticeship which incorporated a period of study under the supervision of an experienced attorney. This usually encompassed the reading of the works considered at the time to be the most authoritative on the law, such as Edward Coke's Institutes of the Lawes of England, William Blackstone's Commentaries on the Laws of England, and similar texts.

The scholastic independence of the law student is evident from the following advice of Abraham Lincoln to a young man in 1855:

If you are absolutely determined to make a lawyer of yourself the thing is more than half done already. It is a small matter whether you read with any one or not. I did not read with any one. Get the books and read and study them in their every feature, and that is the main thing. It is no consequence to be in a large town while you are reading. I read at New Salem, which never had three hundred people in it. The books and your capacity for understanding them are just the same in all places. [...] Always bear in mind that your own resolution to succeed is more important than any other one thing.

Historically, country lawyers or county-seat lawyers were more likely to have read law. Reading law to become an attorney would be the norm, until the 1890s, when the American Bar Association, formed in 1878, began pressing states to limit admission to the Bar to those persons who had satisfactorily completed several years of post-graduate institutional instruction.

On July 8, 1941, James F. Byrnes became the last Justice appointed to the Supreme Court of the United States who had never attended college or law school, and he was the penultimate appointee who had been admitted to practice by reading law. Byrnes was followed by Robert H. Jackson, who was commissioned just three days later, on July 11, 1941, and had also been admitted to the practice of law by reading, although he had attended Albany Law School for less than one year, taking a two-year program in a single year to save money.