Vorderman will be joined by Ryan Thomas and Sayeeda Warsi to discuss the day's top stories, while Simon Rimmer will be cooking up something fabulous in the kitchen.
During the episode, there will be lifestyle and consumer stories as well as celebrity guests, real-life features and the latest news.
Ahead of her appearance on the show, Vorderman said: "It will be 41 years to the month from when, at Yorkshire TV Studios in Leeds, I recorded my first ever TV show, the first ever Countdown, which became the first ever TV programme on Channel 4 back in 1982.
"I lived in Lucky Leeds for very many years and went there for about four months a year for 26 years all together.
"Mum and I always called it Lucky Leeds and it holds only utter love and happy memories, so hosting Steph's Packed Lunch will be a wonderful closing of a circle."
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She continued: "To be back in Leeds, hosting a Channel 4 show, and then handing over to Countdown… just a joy. I just hope I don't burst into tears remembering all those times with Richard Whiteley."
Steph McGovern, who usually hosts the show, will return on Thursday 14th September.
Steph's Packed Lunch is a live lunchtime show featuring celebrity guests, chefs cooking up daring dishes in the kitchen and the biggest entertainment, lifestyle and consumer stories making the headlines.
Steph's Packed Lunch airs live on Channel 4, every weekday from midday. Steph McGovern returns on Thursday 14th September.
Check out more of our Entertainment coverage or visit our TV Guide and Streaming Guide to find out what's on.
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