Path (stylized as PATH) is a network of underground pedestrian tunnels, elevated walkways, and at-grade walkways connecting the office towers of Downtown Toronto, Ontario, Canada. It connects more than 70 buildings via 30 kilometres (19 mi) of tunnels, walkways, and shopping areas. According to Guinness World Records, Path as of 2016 was the largest underground shopping complex in the world, with 371,600 square metres (4,000,000 sq ft) of retail space which includes over 1,200 retail fronts. In 2023, it was surpassed in length by Reso in Montreal. As of 2016, over 200,000 residents and workers use the Path system daily with the number of private dwellings within walking distance at 30,115.

The Path network's northern point is the Atrium on Bay at Dundas Street and Bay Street, including a now-closed tunnel to the former Toronto Coach Terminal, while its southern point is Waterpark Place on Queens Quay. Its main north–south axes of walkways generally parallel Yonge and Bay Streets, while its main east–west axis parallels King Street.

There is continuous expansion of the Path system around Union Station. Two towers being built as part of CIBC Square will be linked to the Path system, extending it to the east to cross over Yonge Street by a pedestrian bridge into the Backstage Condominium building (Esplanade and Yonge corner), giving closed access to Union Station, Scotiabank Arena, and other buildings in Toronto's Financial District.

The Path is open 24 hours a day, 7 days a week, although some access points may have limited hours or be closed on weekends.

In 1900, the Eaton's department store constructed a tunnel underneath James Street, allowing shoppers to walk between the Eaton's main store at Yonge and Queen streets and the Eaton's Annex located behind the (then) City Hall. It was the first underground pedestrian pathway in Toronto and is often credited as a historic precursor to the current Path network. The original Eaton's tunnel is still in use as part of the Path system, although today it connects Toronto Eaton Centre to the Bell Trinity Square office complex on the site of the former Annex building.

Another original underground linkage, built in 1927 to connect Union Station and the Royal York Hotel, remained an integral part of the Path network for many years until it was replaced by a newer connection between the Royal York Hotel and Royal Bank Plaza, which continues onward to Union Station.

The network of underground walkways expanded under city planner Matthew Lawson in the 1960s. Toronto's downtown sidewalks were overcrowded, and new office towers were removing much-needed small businesses from the streets. Lawson thus convinced several important developers to construct underground malls, pledging that they would eventually be linked. The designers of the Toronto-Dominion Centre, the first of Toronto's major urban developments in the 1960s (completed in 1967), were the first to include underground shopping in their complex, with the possibility of future expansion built in. The city originally helped to fund the construction, but with the election of a reform city council this practice ended. The reformers disliked the underground system, agreeing with Jane Jacobs's notion that an active street life was important in keeping cities and neighbourhoods vital and that consumers should be encouraged to shop on street level stores rather than in malls (whether they be above ground or below). However, the system continued to grow because developers bowed to their tenants' wishes and connected their buildings to the system. This also converted low-valued basements into some of the most valuable retail space in the country.

The next expansion of the network occurred in the early 1970s with the construction and underground connection of the Richmond-Adelaide Centre office tower with the Sheraton Centre hotel complex.