Rosler, who steered Brentford to promotion from League One in 2012 before subsequent stints at Wigan Athletic and Leeds United, will now take the reins at Highbury Stadium.
"I'm absolutely delighted to have an agreement in place and I am now really looking forward to starting work. Fleetwood is a special club with a special recent history in the way they have grown the club and the facilities, as well as winning so many promotions to now be playing in League One. I had several options in the UK and abroad but I was waiting for an opportunity and challenge like this to come along," he told the club's official website.
"The discussions I had with the owner Andy Pilley and technical director Gretar Steinsson really impressed me and I feel I can put my stamp on Fleetwood Town. I am very ambitious and I know the owner is too, we all want to be successful here together. The club is a huge success story so far and hopefully I can now help write a new chapter."
Chairman Pilley added: "I'm absolutely delighted to have agreed a deal to name Uwe Rosler as our new head coach. He's a hugely experienced, respected and knowledgeable coach in the game and the fact we have been able to attract him to Fleetwood Town shows just how far we've come.
"We had an incredible level of applicants for the job and we are delighted to say Uwe was our number one choice. His attacking style of football is something which excites me and I'm sure excites the fans of Fleetwood Town. We are now looking forward to a new era at Highbury."
Rosler's first competitive match in charge of the club comes away to newly-promoted Northampton Town next Saturday.