The £5 vibrant yellow coin is the final one to be released in the series, which also features Mr Happy and Little Miss Giggles with Mr Strong.
All three coin designs have been created by Adam Hargreaves son of creator Roger Hargreaves, to celebrate the characters’ 50th anniversary.
Brilliant uncirculated versions of the coins feature the latest colour printing techniques showcasing the characters in vivid colour.
TV and radio presenter Jenni Falconer, who unveiled the final coin, said: “Collecting coins is such a fun family hobby, and the Mr Men and Little Miss designs will be treasured for years to come.”
The coins are available as gold and silver proof editions, as well as brilliant uncirculated editions. A brilliant uncirculated Little Miss Sunshine coin in colour is priced at £22.50, with a gold version costing £2,315.
The coin will not be entering general circulation, the Mint said.