The first new Mr Men character to join the collection in six years will debut in March.
Mr Nobody is an original Roger Hargreaves character and was discovered while Egmont was exploring archive material. Printed over 20 years ago, the book brings the total number of classic Mr Men titles - represented by Chorion - to 47.
Roger's son, Adam Hargreaves, said: "My father would be delighted that Mr Nobody has returned to be enjoyed by new Mr Men fans. He's invisible so it's no surprise that he's been elusive and I am thrilled he has been found."
The first Mr Men title was Mr Tickle in 1971 and the last was Mr Good in 2004. Over 100 million Mr Men titles have been sold worldwide since they were first published.
David Riley, MD of Egmont Publishing Group, said: "We are excited to have discovered Mr Nobody. He is a wonderful addition to the much loved classic Mr Men range."
Mr Nobody will be published on March 1st, priced at £2.50.