The Spice Girl will have a go at being an armchair critic on the Channel 4 show's Stand Up To Cancer special and said it is for her father Martin Brown, who died in March 2017 following a battle with myeloma cancer.
She will join her friend Ruby Wax on the sofa, reported the Mirror.
“My big, strong, beautiful dad was just 63 when he died after a long battle with multiple myeloma cancer," said the 47-year-old.
“I miss him every single day."
Mel went on: "He loved to watch telly and he loved to laugh, so I’m doing this for him and for everyone else out there who has lost someone to cancer.”
The singer has been in the headlines in recent days because she is thought to have got engaged to her hairdresser boyfriend Rory McPhee.
The pair have been dating for around three years and McPhee apparently popped the question to Mel when the couple headed off for a romantic getaway in Berkshire.
The Sun said that he proposed at Cliveden House with a stunning pear-shaped diamond ring and that Mel said yes.
Olympic gold medallist Tom Daley and his husband Dustin Lance Black will also be sharing their thoughts on the latest TV.
Gogglebox's Stand Up To Cancer special is at 9pm on Channel 4 tonight (28 October).
Watch: Scary Spice set to tie the knot: Mel B is engaged!