An Old European Cut diamond is a type of diamond cut that was popular in the late 19th and early 20th centuries, particularly in Europe. It is a predecessor to the modern round brilliant cut and was developed before the technology to cut diamonds to precise proportions existed.

Old European Cut diamonds have a round shape with a high crown, small table, and large culet, which is the flat or pointed bottom of the diamond. They also have fewer facets than modern diamonds, typically around 58 facets or fewer. The result is a diamond with a softer, more romantic appearance, with larger, more dramatic flashes of light, rather than the smaller, more numerous sparkles of modern diamonds.

Old European Cut diamonds were cut by hand, so each diamond is unique and has its own character. They are considered antique diamonds and are often sought after by collectors and those who appreciate the vintage look. However, because of their less precise cutting and the fact that they were often cut for weight rather than brilliance, they may not have the same fire and brilliance as modern diamonds.