Falcons sign SA-born flank
The 30-year-old has spent the past three seasons at Glasgow Warriors, where he won the Pro12 title last year.
Born in Johannesburg, South Africa, Holmes made 29 Pro12 appearances for the Warriors.
The former Western Province and Stormers player will be involved with the Falcons during Saturday's pre-season friendly against Nottingham.
"It has been great so far," Holmes said.
"Everything has happened very quickly but I have really enjoyed it.
"I got a text on the Wednesday saying the Falcons wanted to take me on trial, I drove straight down and was training with them the next day.
"I spent the following week away with the squad at their training camp in Yorkshire and have now signed up full-time. It's great how it has worked out."
Falcons Director of Rugby Dean Richards is delighted to have landed Holmes to the club.
"Tyrone is a good player who spent last week with us on our training camp in Yorkshire, and made a very favourable impression," Richards said.
"He has had a couple of injuries but is back to his best now, and he has a big part to play.
"Defensively he is very strong, he is good over the ball and he carries well. It is great to have him on board."
Holmes' single senior Scotland cap came two years ago against South Africa.
