Mary Louise McLaughlin (September 29, 1847 – January 19, 1939) was an American ceramic painter and studio potter from Cincinnati, Ohio, and the main local competitor of Maria Longworth Nichols Storer, who founded Rookwood Pottery. Like Storer, McLaughlin was one of the originators of the art pottery movement that swept the United States.

Mary Louise McLaughlin was born to a wealthy family of Cincinnati, her father being the owner of a successful dry goods company in the city. Her older brother was architect James W. McLaughlin. Showing an artistic ability at a young age, McLaughlin did not take formal art lessons until 1871 at a private school for girls. At Cincinnati's School of Design in 1874, McLaughlin took a porcelain painting class offered by a Mr. Benn Pitman. During an exhibition by Mary Longworth Nichols Storer at the school that same year, McLaughlin's interest in painting china ripened.

In 1875 the two women's works were featured at The Centennial Tea Party to critical acclaim, and in 1876 both women had exhibitions at the Centennial Exhibition in Philadelphia, Pennsylvania. While at the exhibition McLaughlin was especially taken by the works presented by Haviland & Co. of France, who showcased pieces that featured paintings using the underglaze technique. Since this was a unique advancement at the time, McLaughlin returned to Cincinnati with the determination to figure out the secret to their method. She also wrote a book on china painting upon her return which sold many copies (China Painting: A Practical Manual for the Use of Amateurs in the Decoration of Hard Porcelain). McLaughlin sold more of her works at the exhibition than Storer did, thus starting a competition of sorts between the two women.

In 1877 she figured out how to paint the porcelain under the glaze, and consequently became the first artist in the United States to implement the underglaze technique. Eventually other artists began utilizing this same technique, and in 1879 McLaughlin founded the Cincinnati Pottery Club. While it might seem logical that Storer would join the group, she declined an invitation to do so. This rivalry is likely what caused her to start Rookwood Pottery in the first place. Each member of the club had their pottery made at the Frederick Dallas Hamilton Road Pottery factory, and they would meet at the Women’s Art Museum Association located on fourth street in downtown Cincinnati. Eventually the group moved their meeting to the Dallas shop when the association moved to Cincinnati Music Hall. When Rookwood Pottery was opened, many of the workers from Frederick Dallas joined her team and effectively hindered some of the aspirations of McLaughlin and her group.

In 1880 she published another work, this one titled Pottery Decoration under the Glaze. By this time the technique was already being implemented in other parts of the country. That following year Frederick Dallas died and his shop closed, leaving McLaughlin and her club to rent a room at Rookwood Pottery. In 1883 Storer evicted the club due to the conflict of interest involved in housing them, though she continued to have her pottery pieces made at Rookwood. While the club continued to showcase their work, they were outshined by Rookwood during their tenure. This in part caused McLaughlin to take up portrait painting in the 1890s, taking classes from Frank Duveneck in what was his first painting lesson. In 1890 Rookwood had changed ownership, and a William W. Taylor was the new owner. Taylor, under the direction of Storer, started making claims that McLaughlin was not the true discoverer of the underglaze method. He went so far as to demand the statement by Clara Chipman Newton in a 1893 pottery catalog stating McLaughlin was the founder of the technique in America be withdrawn. This never happened, but the incident effectively terminated any remnants of a relationship the two women had once shared.

In the 1890s Mclaughlin returned to pottery, this time working out of her own backyard in the studio pottery style (the hardest of its kind). She effectively went from painting porcelain to creating it. In 1906 she gave up pottery and began writing again. She died January 19, 1939 at age ninety-one and is buried in Spring Grove Cemetery.