كتب : وكالات
"I'm really happy to be here at Arsenal, it is a great day for me," Rosicky was quoted as saying by Arsenal's official website.
"This is the best club in Europe and I will give everything for Arsenal," added Rosicky who featured 31 times in the UEFA Champions League with Dortmund and former side Sparta Prague.
Rosicky made his international debut at the age of 17 and represented his national side in the European Cups in 2000 and 2004.
He played a key role in his side's campaign towards their first appearance ever in the World Cup when he scored the decisive winner against Norway in the play-offs.
The 25-year-old attacking midfielder said Arsenal's impressive display in the Champions League convinced him of joining the Gunners.
"The team showed its strength recently in the Champions League and it has big potential with a lot of young players, I think we can be even better next season," he said.
Arsenal coach Arsene Wenger said that Rosicky enjoys skills and experience that will add to Arsenal's strength.
"He (Rosicky) has great technique, skill on the ball and sharp passing," the Frenchman said after signing the contract.
"Tomas has good experience at all levels for club and country, and we look forward to welcoming him to Arsenal after what will hopefully be a successful summer for him at the World Cup."
Rosicky is Arsenal's first new signing in the off-season after securing the services of skipper Thierry Henry till 2011.