On Little House on the Prairie, Harriet Oleson is quite a Brash personality, someone who always is in everyone else’s business, and she can be quite rude to people who she thinks are not as important as her.
But was Harriet Oleson based on a real person? The answer is a bit more complicated than yes or no. technically, Harriet Oleson is based on a real person. But here is why it is a bit more unusual.
In the original Little House series written by Laura Ingalls Wilder, Laura changed the names of a few people, because she was portraying them in a somewhat negative light. One of those people was Nellie Oleson. Nellie Oleson was technically the combination of three girls that Laura knew when she was younger. And one of those girls was Nellie Owens, parents owned the mercantile in Walnut Grove. So when describing Harriet, the closest real person to that would be Nellie Owens’s mother.
Nellie’s mother was actually named Margaret Owens, not Harriet. And by all accounts, Margaret was a lovely person who many people liked in Walnut Grove. So she was quite the opposite of how she is portrayed on the show. So the character Harriet Oleson was not based on the real Margaret Oleson, the only real similarities were that she had children named Nellie and Willie, and she and her husband owned the mercantile in Walnut Grove.
So while yes, Harriet Oleson was technically a real person, the person she was based on was named something different and had a very different personality from the one portrayed on the show.