The actress, who was best known for playing Harriet Oleson in the period drama, died yesterday.
Her representative Tony Sears told NBC Katherine died at the Motion Picture and Television Fund retirement community in Los Angeles, California.
The star played nasty mother Harriet on the hit NBC show from 1974 until its final episode in 1983.
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“So I began mixing farce into it. I think the audience counts on seeing Mrs Oleson fall on her fanny.”
Stars of the show have paid tribute to the actress following the news of her death, with Melissa Gilbert sharing a lengthy posy on Instagram.
“I just got word that Katherine MacGregor based away yesterday,” she said. “This woman taught me so much… about acting… vintage jewellery… life.
“She was outspoken and hilariously funny. A truly gifted actress as she was able to play a despicable character but with so much heart.
“The thing people outside of our Prairie family didn’t know, was how loving and nurturing she was with the younger cast,” she continued. “I really loved her and I find great comfort in knowing that she is at peace and, per her beliefs, her soul has moved on to its next incarnation.”
Katherine was raised in Fort Collins, Colorado, and moved to New York to study acting in 1949.
Her on-screen career boasted a handful of movie and TV roles before she landed the part of Harriet in Little House on the Prairie.
She went on to become a fan favourite as the antagonist in the long-running period drama, starring in over 150 episodes.