Waltham is an inner suburb of Christchurch, New Zealand, located approximately two kilometres south-east of the city centre. State Highway 76, part of Christchurch's ring road system, and known there as Brougham Street, runs through the suburb, as does the Lyttelton Line rail corridor.

Lyttelton Line is a name sometimes used to refer to the section of the Main South Line in New Zealand's South Island between Lyttelton and Christchurch, and can also be used to refer to the operations on this section. As it has always been part of the Main South Line, this name has never been officially used to refer to the track itself.