Approved by the Duke and Duchess of Cambridge, Her Majesty the Queen and the Chancellor of the Exchequer and designed by respected engraver John Bergdahl; the coin is decorated with harp-playing cherubs encircled by swags of lilies - which are also included on Prince George's christening coin.
The coin - which will be available in silver and gold - bears the inscription, "To celebrate the Christening of Princess Charlotte Elizabeth Diana of Cambridge 2015".
Shane Bissett, Director of Commemorative Coin and Medals at The Royal Mint said: "These coins will be a fitting addition to The Royal Mint's long tradition of creating works of art to celebrate landmark events in the history of the Royal family. It is entirely appropriate that we commemorate this significant occasion with the release of a special coin, just as we celebrated the christening of Prince George."
A special limited edition £5 coin, also designed by John Bergdahl, was issued by The Royal Mint to mark the birth of Princess Charlotte on 2nd May 2015. Her christening will take place on 5 July at St Mary Magdalene Church at Her Majesty the Queen's Sandringham estate in Norfolk.
Mario Testino to photograph Princess Charlotte's christening
Britain's Princess Charlotte's christening will be photographed by her late grandmother Princess Diana's favourite photographer Mario Testino.
The photographer - who was one of Charlotte's late grandmother Princess Diana's favourites - has been chosen by the Duke and Duchess of Cambridge to take the official pictures for their daughter's christening at St Mary Magdalene Church, Norfolk, this Sunday.
Mario - who took Prince William and Princess Kate's official engagement portraits in 2011 and famously captured Vanity Fair's portraits of Diana before her death at age 36 in 1997 - will shoot the main portraits of the christening party after the ceremony, and is "overwhelmed" to be chosen.
In a statement, the 60-year-old photographer said: "I am overwhelmed and honored to be chosen to document this occasion and to carry on the documentation of the family that is the soul of this country, a country that has given me so much."
The portraits will likely include one of the Duke of Cambridge, the Duchess of Cambridge, Princess Charlotte and her brother Prince George as well as Queen Elizabeth and both sets of grandparents.
The statement from Kensington Palace added: "The Duke and Duchess are delighted that Mario Testino will help capture this important moment for their family and look forward to sharing the photographs with the public."