Writing on Twitter, Justin Welby said "Praying for a safe mission as you lift off tomorrow @astro_timpeake. Godspeed!"
Praying for a safe mission as you lift off tomorrow @astro_timpeake. Godspeed!
— Justin Welby ن (@JustinWelby) December 14, 2015
Major Peake, 43, is the first fully British professional astronaut.
He'll blast off from the historic Launch Pad 1 in Kazakhstan at 11.03 on Tuesday.
He's been training for the mission for the past two and a half years.
The trip will cause him to miss Christmas with his family - wife, Rebecca, and children Thomas, six, and Oliver, four.
Speaking at a press conference on the eve of his historic launch, he said: "You know, we've been so busy focused on this mission that I kind of forgot Christmas was just over a week away.
"Of course we'll be enjoying the fantastic view of Planet Earth and our thoughts will be with everybody on Earth enjoying Christmas, and with our friends and family, of course.
"We'll thankfully be able to give them a call on Christmas Day.
"I also hear a Christmas pudding went up on Orbital Four (a supply mission to the space station), so we'll have some treats as well."
Major Peake will travel to the International Space Station in the Soyuz FG rocket. On Monday a number of Russian Orthodox priests held a service to bless the rocket.