The country that remained neutral during World War II but received funding through the Marshall Plan was Sweden.
The goal of the Marshall plan was to provide economic assistance to countries to not only help those who faced damages during World War II, but also to help European countries in general to remain economically stable. The reason the US did this was to ensure that none of these countries would fall under the control of the communist Soviet regime. This is why a country like Sweden received aid despite being neutral during this war.