The 28-year-old paceman has become a vital member of the Baggy Green's attack and is currently preparing for the forthcoming Ashes series in Australia.
He has taken time out to confirm his switch to England, though, and no international commitments mean he will be available for all Nottinghamshire's County Championship games - although he will not feature in Twenty20 cricket.
"I've always wanted to spend a season in county cricket and this feels like the right opportunity at a time when Australia have no Test matches scheduled," said Siddle.
"Nottinghamshire have an excellent pedigree and they're keen to challenge on all fronts which really appeals to me."
Siddle will now line up in club colours alongside England duo Stuart Broad and Graeme Swann, hoping to have added considerably to his current tally of 167 Test wickets by then.
He has made 46 appearances in Test cricket and become a reliable member of Michael Clarke's attack, building his reputation on hard work and a hat-trick in the Ashes opener at Brisbane in 2010.
"Peter was always our number one target and we're very pleased to have secured his services," Nottinghamshire director of cricket Mick Newell added.
"He was very keen to join us and everyone that we have spoken to has endorsed him as a player and as a person. He'll add a lot of quality to our ranks, he'll be an excellent role model for the younger players in our squad and his wicket-taking ability will lift us."
Newell has also been impressed with Siddle when he has seen him on English soil.
"He was excellent over here during the Ashes series," he said.
"He has a track record of taking wickets all over the world and I'm hopeful that he can exploit the conditions at Trent Bridge.
"Our draws and batting bonus points kept us out of trouble last season but we need to find ways to win more four-day matches and strengthening our seam attack is our best method of doing that."
As well as County Championship games, Siddle will also be lining up for Notts in the CB40 competition.