James Breckenridge Speed (middle name sometimes spelled Breckinridge) (1844-1912) was a successful businessman in Louisville, Kentucky and an important philanthropist.

Although he was born in Mississippi and only came to Louisville as an 11-year-old, James B. Speed was always considered a Louisvillian. His parents and siblings were all born in Louisville, and his family was the famous and powerful Speed family, which had had a great impact on the city. His father, also James Speed, was United States Attorney General under Abraham Lincoln and Andrew Johnson.

James B. Speed was a financial leader who strongly influenced Louisville's development. He helped to establish Louisville's street railway system, and became the president of the Louisville Street Railway Company. He saw early how significant cement would be in the growth of America, and he became the president of the Louisville Cement Company. He developed and operated large coal interests, and served as president of the Ohio Valley Telephone Company.

As a philanthropist, he donated a statue of Abraham Lincoln which stands in the State Capitol, and he helped to establish and maintain several schools. After his death, his wife, Hattie Bishop Speed, set up a foundation in his name which helped to found the Speed Art Museum and the Speed Scientific School.

He died in 1912 in Rockland, Maine, where he spent his summers, and he was buried in Cave Hill Cemetery in Louisville.