A supermoon occurs when the Moon is in the closest part of its orbit to Earth, meaning it appears larger in the sky.
The eclipse - which made the Moon appear red - has been visible in North America, South America, West Africa and Western Europe.
This phenomenon was last observed in 1982 and will not be back before 2033.
But the definition of a supermoon is debated among astronomers.
Skywatchers in the western half of North America, the rest of Europe and Africa, the Middle East and South Asia saw a partial eclipse.
From the UK, observers watched the Moon pass through the Earth's shadow in the early hours of Monday morning. In North and South America the eclipse was seen on Sunday evening.