The 34-year-old young leader shared photographs of her on her Instagram account, where the couple was seen posing together while holding a bunch of white flowers.
“I am happy and grateful that I get to share my life with the man I love,” she wrote in a post on Instagram.
The wedding took place at Kesaranta, the prime minister’s official residence, on Saturday and was attended by the couple’s family and closest friends, Finland’s government said.
The couple has been together since they were teenagers and have a two-year-old daughter.
Marin became Finland’s prime minister in December and was the world’s youngest serving head of government at the time.