Little House on the Prairie had a varied number of seasons, depending on who you ask.
The original Little House on the Prairie television show ran for eight seasons.
Then the name was changed to Little House: A New Beginning which focused on Laura and Almanzo, and did not feature the rest of the Ingalls family. This consisted of a single season, usually referred to as season 9.
After the series concluded, three TV movies were released, and these 3 are often referred to as season 10.
Most people consider the show as having nine seasons though, with additional TV movies which aired later.