Kruger was always expected to leave Baltimore with the team tight on salary cap space and the 27-year-old keen to cash in on a Super Bowl-winning season with the Ravens.
The second round pick from the 2009 draft has signed a five-year deal with the Browns worth $40 million, with Cleveland keen to spend the money they have accumulated under the salary cap.
Kruger recorded nine sacks in the regular season and 4.5 during the play-offs, although he did not see that much playing time during the Super Bowl in New Orleans.
He is still among the best pass rushers available on the market this off-season and he will now be required to step-up and lead Cleveland's defensive unit.
"We are very excited about the addition of Paul Kruger to our team," new Browns coach Rob Chudzinski said in a statement.
"He is a talented linebacker who is going to make an immediate impact on our defence. When you put on the film, you see physicality, explosive pass rush and a high motor. He has been very productive for the Ravens and proved it at the highest level last season in the play-offs."
Browns CEO Joe Banner added that the team had singled out Kruger as their top priority in free agency and was delighted to get their man so quickly.
"Paul is the type of player we were looking to bring on at the outset of free agency, and we are thrilled that we were able to sign him," said Banner.
"Not only do we feel strongly about his ability as a football player, but he will add a great deal from a leadership standpoint as well. He has exhibited marked improvement each year of his career and we believe he can help the Cleveland Browns for many years to come."