The Hampstead Junction Railway was a railway line in north-west London, England, opened in 1860. It connected the existing North London Railway at Camden with the North and South Western Junction Railway. It ran through open country but encouraged residential building, providing passenger train connections with the City of London, as well as connecting other lines. It was absorbed by the North London Railway in 1867. Its route remains in use today with the passenger trains of the North London line as well as heavy freight traffic.