Dorothy Sloop (September 26, 1913 – July 28, 1998), also later known as Dorothy Sloop Heflick, was an American jazz pianist who performed with female jazz bands. A native of Ohio, her nickname was Sloopy, and she was the inspiration behind the song "Hang On Sloopy" by the Dayton, Ohio rock band The McCoys. The No. 1 single became the official rock song of Ohio in 1985 and is used by the Ohio State University marching band.
She was born into a Roman Catholic family in Steubenville, Ohio. She learned piano as a youth and began performing in local theaters as young as age six, including a concert with another Steuebenville native, Dean Martin. She studied for a year at Ohio University.
Sloop left college and relocated to New York City where she formed a jazz quartet, the Southland Rhythm Girls, with singer and clarinetist Yvonne "Dixie" Fasnacht. They moved to Fasnacht's hometown New Orleans, Louisiana, and played in Dixie's Bar of Music, a bar on Bourbon Street owned and run by Fasnacht. In 1957, they recorded the album Dixie and Sloopy.
Sloop worked returned to Steubenville, and she earned her college degree and later a master's degree. For thirty years, she taught special education in St. Petersburg, Florida. She continued to perform on jazz piano into her 70s.
Sloop was married once, to Joe Boudreaux. They moved to Steubenville, then divorced. Their daughter Jane Heflick was given a different surname, the maiden name of one of Dorothy's grandmothers.
Dorothy Sloop died at age 85 in 1998.