It's the third time she has been unable to perform there, with Covid forcing a show to be cancelled last year. She pulled out in 2019 after haemorrhaging her vocal cords.
Bosses at Forestry England have said the concert cannot be rescheduled and anyone who bought a ticket will be contacted and offered a refund.
The popular singer was due to perform as part of Forest Live 2022 in June, with other performers including Keane, Noel Gallagher's High Flying Birds and Rag'n'Bone Man.
A spokesman for Forestry England said: "We are sorry to announce that, due to unforeseen circumstances, Jess Glynne’s concerts as part of Forest Live this summer have been cancelled.
"These dates are: Cannock Chase Forest, Staffs - Thursday 9 June; Westonbirt Arboretum, Glos - Sunday 12 June; Thetford Forest, Suffolk - Sunday 19 June.
"Customers for these performances will be contacted by their point of purchase with refund information.
"Unfortunately, these concerts cannot be rescheduled so Forestry England will be securing a new headline artists for these dates.
"We apologise for any inconvenience caused."