The first coin with King Charles III's image on it is one with Albus Dumbledore from the Harry Potter series.
The coin is the third in a series celebrating the 25th publishing anniversary of Harry Potter and the Philosopher's Stone.
On the coin's "heads" side is a picture of the King, and on the reverse is a picture of the Hogwarts wizard.
The royal portrait will change on "one of a small number" of coin collections, according to the Royal Mint.
In the series' first two coins, which featured images of Harry Potter and Hogwarts, there was a picture of the late Queen Elizabeth II.
Jim Kay, the artist who produced the first Harry Potter and the Philosopher's Stone edition with all illustrations, is represented on all three coins.
Some of the coins in the collection are colored, and others have a "latent feature" that rotates in the light to reveal a lightning bolt and the number "25" to commemorate the series' 25th anniversary.
The Royal Mint claimed that the coins were popular around the world. Harry Potter fans have so far purchased at least one coin from the range in 86 different countries.
Prices for the collector's items start at £11, even though the designs are on a 50p.
Fans can pay £20 for a colour version, and up to £5,215 for a £200 denomination gold coin.
"We are thrilled to be continuing our enthralling Harry Potter coin collection with Professor Albus Dumbledore featuring on his very own 50p," said Rebecca Morgan, director of collector services.
Due to the popularity of the books and the fact that this collection is one of a select few that will have its portrait changed throughout the series, the Harry Potter coin collection from the Royal Mint has attracted collectors from all over the world.
This collection of coins acts as a lasting remembrance of the fascinating transition from Britain's longest-reigning monarch to His Majesty the King's debut on UK coinage. ".
In 1997, JK Rowling's Harry Potter and the Philosopher's Stone was initially published. With sales of more than £500 million worldwide, the books about the hidden wizarding world expanded into a seven-part series.
