The Y-block engine is a family of overhead valve V8 automobile engines produced by Ford Motor Company. The engine is well known and named for its deep skirting, which causes the engine block to resemble a Y. It was introduced in 1954 as a more modern replacement for the outdated side-valved Ford Flathead V8 and was used in a variety of Ford vehicles through 1964.

The Ford flathead V8 is a V8 engine with a flat cylinder head designed by the Ford Motor Company and built by Ford and various licensees. During the engine's first decade of production, when overhead-valve engines were used by only a small minority of makes, it was usually known simply as the Ford V‑8, and the first car model in which it was installed, the Model 18, was often called simply the "Ford V-8", after its new engine. Although the V8 configuration was not new when the Ford V8 was introduced in 1932, the latter was a market first in the respect that it made an 8-cylinder affordable and a V engine affordable to the emerging mass market consumer for the first time. It was the first independently designed and built V8 engine produced by Ford for mass production, and it ranks as one of the company's most important developments. A fascination with ever-more-powerful engines was perhaps the most salient aspect of the American car and truck market for a half century, from 1923 until 1973. The engine was intended to be used for big passenger cars and trucks; it was installed in such until 1953, making the engine's 21-year production run for the U.S. consumer market longer than the 19-year run of the Ford Model T engine for that market. The engine was on Ward's list of the 10 best engines of the 20th century. It was a staple of hot rodders in the 1950s, and it remains famous in the classic car hobbies even today, despite the huge variety of other popular V8s that followed.