A new taskforce will "accelerate" house building in Northstowe.
Ms Reeves made the announcement in her first speech since being appointed Chancellor after Labour won a majority in the general election last week.
She highlighted the town as one of four areas in the country where she wanted to "accelerate stalled housing sites", which also included Liverpool Central Docks, Worcester Parkway and Langley Sutton Coldfield.
The first phase construction in Northstowe has seen over 1,000 homes built so far, and once completed, the new town is expected to be made up of 10,000 homes.
Ian Sollom, the newly elected MP for the St Neots and Mid Cambridgeshire constituency – which includes Northstowe – has welcomed the announcement.