The White Line (French: Ligne blanche), also known as Line 7 (French: Ligne 7), was a proposed line of the Montreal Metro that never made it past its planning stage.
Proposed by the Bureau des Transports de Montréal (BTM) in September 1983, the original project for the new north-south Line 7 was for ten stations, from Pie-IX to Léger, under Boulevard Pie-IX, through Saint-Léonard and north-east towards Rivière-des-Prairies. A year later, at the start of 1984, it was formally proposed by the Communauté urbaine de Montréal (CUM), with 12 stations (from Pie-IX to Maurice-Duplessis/Langelier).
For nearly a decade (1980-1990) the line appeared on all official Métro maps, colored white, so it received the unofficial nickname of "White line". Other nicknames include "Pie-IX line".
The Métro system has another projected subway line, Line 6, whose number was reserved for a surface line proposed by the Ministère des Transports du Québec (MTQ) along the northern shore of the island, but it was never shown on a system map.
Detailed studies on Line 7 are archived at the Grande Bibliothèque, covering the proposed route, station location options, ridership flux, and so on.