The B141 ran along part of High Road, New Southgate, in north London. Owing to the road's short length its history is not fully known. It was originally unclassified but gained its number in the second quarter of the 20th century.
The road started where the A109 turned onto Station Road and then headed north along High Road for the last stretch to New Southgate, where it met the A109 once more. The B141 has now been declassified again, despite being a shorter route than that taken by the A109, and much of it has been closed to vehicular traffic.