Councillor Dan Harrison, who was first elected to the council in 2017 to represent Ibstock and Appleby and is in his second term at County Hall, has taken over the role.
He succeeds Councillor Pam Posnett MBE, the Melton East ward member, who served as chair for two years.
Councillor Harrison is a former British international judo player and now teaches the sport to school children, as well as anti-bullying and stranger awareness classes.
He will be supported in his year of office by his daughter, Daniella Rushton, and has chosen Dementia UK as his charity for the year – a cause close to his heart.
Councillor Harrison said: “I am delighted to be taking up the position of chairman of the county council, it is a great honour and I am looking forward to carrying out my civic duties around the county.
“I particularly look forward to meeting residents and getting to know more about our local communities.”
He added: “I have chosen Dementia UK as my charity for this year.
“It is a cause very close to my heart as a much-loved family member suffers from this distressing condition. We often think of dementia as something which affects just the elderly but this is not the case and there are few of us whose lives have not been touched by dementia in some way, whether in our own families or those of our friends.
“I hope to raise as much money as possible to support research into dementia and to help provide more support and help for those who need it most.” Councillor Dr Kevin Feltham, a member for 20 years, will serve as vice-chair.