Great Portland Street is a street in the West End of London. Linking Oxford Street with Albany Street and the busy A501 Marylebone Road and Euston Road, the road forms the boundary between Fitzrovia to the east and Marylebone to the west. In administrative terms it is in the City of Westminster. Like the better known Portland Place which runs parallel with it to the west, Great Portland Street was developed by the Dukes of Portland, who owned most of the eastern half of Marylebone in the 18th and 19th centuries. It is now a mixed use street with buildings of mainly five to eight storeys. There are some offices and a number of blocks of mansion flats. Some of the buildings belong to Great Portland Estates and The Langham Estate.
The BBC Trust is based at 180 Great Portland Street  while BBC Radio 1 headquarters is also situated on Great Portland Street in Yalding House. Radio 2 and 6 Music are located at Western House (99 Great Portland St). Virgin Media Television and Virgin Mobile are both based at 160 Great Portland Street. . The Portland Hospital for Women and Children is found at 205-209 Great Portland Street.
A book includes Great Portland Street as one of "London's 50 Outstanding Classical Music Landmarks" because Felix Mendelssohn lodged at #103 during the premiere of Fingal's Cave, and Carl Maria von Weber died there.