The 27-year-old is alleged to have committed the offenses between January 2014 and March 2017 when he was on the books of Norwich City.
Toffolo also spent time on loan at Swindon Town, Rotherham and Scunthorpe during the stipulated period.
The Englishman made 19 Premier League appearances last season as Nottingham retained their top flight status.
An FA spokesperson said: “Nottingham Forest’s Harry Toffolo has been charged with misconduct in relation to our betting rules.
“It’s alleged that the defender breached FA Rule E1(b) 375 times between 22 January 2014 and 18 March 2017. Harry Toffolo has until Wednesday 19 July 2023 to provide his response.”
Back in May, Brentford striker Ivan Toney was banned for eight months after he admitted to breaching the FA's betting rules 232 times over a four-year period.
