A vanity plate (US), prestige plate, private number plate, personalised registration (UK) or personalised plate (Australia) is a special type of Vehicle registration plate on an automobile or other vehicle. The owner of the vehicle will have paid extra money to have his or her own choice of numbers or letters, usually forming a recognisable phrase, slogan, or initialism on their plate. Sales of vanity plates are often a significant source of revenue for North American provincial and state licensing agencies. In some jurisdictions, such as the Canadian province of British Columbia, the vanity plates look totally different from the regular issue plates.

In some states and provinces, optional plates can also be vanity plates and are a choice of motorists who want a more distinctive personalised plate. However, the maximum number of characters on an optional plate may be lower than on a standard-issue plate. For example, the U.S. state of Virginia allows up to 7.5 characters (a space or hyphen is counted as 0.5 character) on a standard-issue plate, but only up to 6 characters on many of its optional plates.

In many jurisdictions, such as New York• and Virginia, a motorist may check the availability of a desired combination online.

All American states and Canadian provinces that issue vanity plates have a "Blue List" of vanity plates that list banned words, phrases, or letter/number combinations. The American state of Florida, for example, has banned such plates as "PIMPALA", whilst the state of New York bans any plates with the letters "FDNY", "NYPD", or GOD, among others.• Often the ban is to eliminate confusion with plates used on governmental vehicles or plates used on other classes of vehicles. However, a licensing authority's discretion to deny or revoke "offensive" vanity plates is finite. For example, some U.S. motorists have successfully sued their state governments on that issue under the First Amendment to the United States Constitution.

In the United Kingdom, number plates are issued by the Driver and Vehicle Licensing Agency. They do not approve personalised registrations if they contain words which are offensive in any (widely used) language. Some plates only acquire significance because of particular owners, e.g. COM 1C was formerly owned by the comedian Jimmy Tarbuck while the unremarkable 1967 plate BEL 12E is owned by the Belizean High Commission and CHN 1 is owned by the Chinese embassy.

In the UK, there are a large number of private dealers who act as agents selling DVLA registrations, as well as their own stock - often purchased at auction or from private sellers.

In Australia the various states offer personalised plate schemes, with some states having a yearly fee to maintain the cherished number. In the Australian state of Queensland the personalised plate scheme helps fund the Road Safety Activities Fund.

As of 2006, Hong Kong also allows such license plates.