The 84 Sheppard West bus route operates between Sheppard-Yonge Station on the Yonge-University-Spadina Subway, the area of Sheppard Avenue West and Weston Road, and the area of Steeles Avenue West and Highway 400, generally in an east-west direction. It also serves the Downsview Station on the Yonge-University-Spadina Subway. Accessible service is provided on the route. Both Sheppard-Yonge and Downsview Stations are accessible subway stations. Bike racks are available on this route.

Three services are operated. The 84 (Sheppard-Yonge Stn-Weston Rd) is the main branch, and operates at all times, seven days a week. The 84A (Sheppard-Yonge Stn-Steeles via Arrow Rd) short-turn branch operates during the peak periods, from Monday to Friday only. The 84D (Sheppard-Yonge Stn-Steeles via Oakdale) short-turn branch also operates during the peak periods, from Monday to Friday only.

Westbound 84 TO WESTON RD

These buses operate from Sheppard-Yonge Station via west on Sheppard Avenue West, through Downsview Station, continuing west on Sheppard Avenue West, and north on Weston Road to Bradstock Road.

Eastbound 84 TO SHEPPARD-YONGE STN

These buses operate from Weston Road and Bradstock Road via east on Bradstock Road, south on Rivalda Road, east on Sheppard Avenue West, through Downsview Station, and continuing east on Sheppard Avenue West to Sheppard-Yonge Station.

Westbound 84A TO STEELES VIA ARROW RD

These buses operate from Sheppard-Yonge Station via west on Sheppard Avenue West, through Downsview Station, continuing west on Sheppard Avenue West, north on Arrow Road, north on Signet Drive, and east on Steeles Avenue West to Rossdean Drive.

Eastbound 84A TO SHEPPARD-YONGE STN

These buses operate from Steeles Avenue West and Rossdean Drive via south on Rossdean Drive, east on Garyray Drive, south on Norelco Drive, west on Fenmar Drive, south on Signet Drive, south on Arrow Road, east on Sheppard Avenue West, through Downsview Station, and continuing east on Sheppard Avenue West to Sheppard-Yonge Station.

Westbound 84D TO STEELES VIA OAKDALE

These buses operate from Sheppard-Yonge Station via west on Sheppard Avenue West, through Downsview Station, continuing west on Sheppard Avenue West, north on Oakdale Road, north on Norfinch Drive, and east on Steeles Avenue West to Jane Street.

Eastbound 84D TO SHEPPARD-YONGE STN

These buses operate from Steeles Avenue West and Jane Street via south on Jane Street, west on Hullmar Drive, north on Peter Kaiser Gate, west on Steeles Avenue West, south on Norfinch Drive, south on Oakdale Road, east on Sheppard Avenue West, through Downsview Station, and continuing east on Sheppard Avenue West to Sheppard-Yonge Station.

All buses on the route serve local bus stops along the route.