Rosa Bonheur painted constantly and though she struggled to receive proper acknowledgement for her work she did receive a French government commission, which lead to her first great success, the Horse Ploughing at the Nivernais, which was in 1849. Her most famous work was the monumental Horse Fair, completed in 1855, which measured eight feet high by sixteen feet wide. It led to international fame and recognition and that same year she travelled to Scotland, and met with Queen Victoria, who admired her work.

In 1860 she completed sketches for a series of large paintings depicting the Scottish Highlands. These artworks depicted a way of life that had disappeared a century earlier and had an enormous appeal to Victorian sensibilities. This made her especially popular in England and less so in her native France.

Bonheur’s life was not without controversy however. She was, in her time, infamous because she was known for wearing men's clothing, something she had to obtain a permit to wear at the time from the local police station and is now seen as an early feminist. She said at the time that this was simply practical, as it suited her work with animals: "I was forced to recognize that the clothing of my sex was a constant bother. That is why I decided to solicit the authorization to wear men's clothing from the prefect of police. But the suit I wear is my work attire, and nothing else. The epithets of imbeciles have never bothered me...."

She was soon considered the most famous woman artist of her time. She worked obsessively and was represented by private art galleries across Europe and in particular with the art dealer Ernest Gambart who would help promote her throughout the United Kingdom.

She lived for fifty years with her female companion, Nathalie Micas, another scandalous affair, at her country estate near Fontainebleau. After Micas' death, she taught and lived with the American painter Anna Elizabeth Klumpke. Rosa continued to paint until she died at the age of 77. Many of her paintings, which had never shown publicly, were sold at auction in Paris in 1900.