North Derby Street is distinguished from Derby Street, which used to be a side-street of Divis Street. It may simply be named after the English city of Derby, but more likely after one of the holders of the title Earl of Derby. Perhaps the most notable was Edward Smith-Stanley, 14th Earl of Derby, who was British Prime Minister in 1852 and subsequently led the Conservative government in the House of Lords while Disraeli led in the Commons.
Jennymount Mill, designed by John Lanyon (son of Sir Charles Lanyon) and built in 1856, is situated in North Derby Street.
Resolved on the application of Messrs Philip Johnston and Sons the Council be recommended to change the name of ‘Beck Street’ to that of ‘North Derby Street’. (TIC, 17th April 1867).