Griggs will work closely with ISES president Richard Foulkes and the incoming board.
She was previously a researcher for live TV shows including Too Many Cooks, Trisha and Loose Women.
Foulkes said: "The operations manager role is critical to ensure we deliver value to members through high quality creative and educational activity as well as managing all our member services. We’re delighted to welcome Toni to the team."
Griggs will join ISES in 19 July following the departure of Steph Laing.
"We are also incredibly sad to see Steph leave the fold and I would like to thank her for her invaluable contribution over the last three years and wish her well in her new role at London Launch," Foulkes added.