Kit Harington and Rose Leslie will take part in their first public performance together since Game Of Thrones.
The stars played Jon Snow and Ygritte in the epic TV drama and wed in real life last summer.
They will give readings at the MS Society’s Carols by Candlelight event in London on December 10.
Leslie, 32, said: “I’ve always loved carol concerts, and I’m really excited for this one.
“My husband and I are looking forward to supporting this wonderful and important charity that offers invaluable support to over 100,000 people living with MS in the UK.”
The pair are supporting the MS Society’s Stop MS Appeal, to raise £100 million to find treatments for everyone with multiple sclerosis.
They will be reading alongside entrepreneur Deborah Meaden, Spooks actress Nicola Walker, Paralympic champion Kadeena Cox and comedian Paul Merton.
The event will also feature a gospel choir led by Jermain Jackman, one-time winner of The Voice.
MS is a chronic condition that affects more than 100,000 people in the UK.
It damages nerves in the body and makes it harder to do everyday things like walk, talk, eat and think.
There are more than a dozen licensed treatments for people with the relapsing form of MS, but none stop the accumulation of disability as MS progresses.
MS Society chief executive Nick Moberly said: “We are incredibly grateful to all our celebrity readers for taking part in one of our most special events.
“MS is relentless, painful and disabling, but we can see a future where no-one needs to worry about MS getting worse. The vital funds raised from events like this will help us stop MS sooner.”
Information is at https://www.mssociety.org.uk/get-involved/fundraise/christmas-carol-service