The photograph was taken by The Duchess in April at the family’s Anmer Hall home in Norfolk.
Charlotte, who turns two on Tuesday 2 May 2017, is wearing a knitted yellow cardigan, decorated with a sheep design.
In a statement Kensington Palace said: “Their Royal Highnesses would like to thank everyone for all of the lovely messages they have received, and hope that everyone enjoys this photograph of Princess Charlotte as much as they do.”
The Cambridges have followed a tradition they set with their daughter’s first birthday and given royal fans a new image of the toddler princess taken by her mother.
Charlotte has been kept out of the public eye for much of the past year, but she was last photographed on Christmas Day when she was taken to a church service close to the home of her grandparents Carole and Michael Middleton in Bucklebury, Berkshire.
The Cambridges will be spending more time at Kensington Palace in London when William leaves his air ambulance helicopter pilot job in the summer and devotes more time to royal duties, PA reports.
Prince George will be schooled at the private Thomas’s Battersea school in September and it is likely his sister will be sent to a nursery later this year.