The Waterdown Branch was established in 1966 and moved to the Mill Street North location in 1979. In December 2015, the Branch moved to its new location, 163 Dundas St. E.
The Branch offers several improved service features including: accessibility, more public-access computers and dedicated study spaces. The Branch now has a bigger collection and a redesigned children's area, which houses kid-friendly technology and activities. With the new layout and larger space, more programs will be offered in the Branch and when the weather is agreeable, a reading patio overlooking Dundas Street and the Escarpment will be opened.