The 1882 work, entitled Under The Birch Trees/Children in a Birch Wood by the Haiko Fjord, was retrieved by a special task force set up by the Polish culture ministry.
Deputy Prime Minister Piotr Gliński, who doubles as culture minister, granted the painting to Warsaw's National Museum at a ceremony on Tuesday.
He said the Paris-educated Edelfelt was an outstanding Finnish realist painter and portraitist whose paintings "are currently highly regarded worldwide."
Over half million works of art lost in WWII: deputy PM
Gliński told those at the ceremony that Poland had lost "over half a million works of art" between 1939 and 1945, and the task force was working to locate them.
He added that 80 restitution proceedings were in progress, including 20 involving artwork looted by the Soviets.
"Each case is different and the passage of time makes the task highly complex," Gliński said.
"But what matters is that Poland has a system for retrieving these lost art items, a system that works," he added.