It is located to the north of the Waitemata Harbour, nine kilometres northwest of the Auckland city centre.

The suburb is located in the northern inland part of North Shore city, and is surrounded by the suburbs of Marlborough, Sunnynook, Forrest Hill, Birkenhead, Northcote and is situated close to Takapuna. The northern part of Glenfield is regarded as a separate suburb known as Glenfield North. This latter suburb is sited close to State Highway 1 as it stretches north towards Albany.

Glenfield has two shopping areas, one which is dominated by a Westfield shopping mall and an Aquatic/sports centre; and the second, Wairau Valley, which has some industrial sections and a large amount of furniture and home stores.

Glenfield has a good number of Primary, Intermediate and Secondary schools ranging in educational quality and social diversity. The closest tertiary centre is Massey University which is situated in Albany, a few kilometres to the north.

In the past Glenfield has been perceived as a working-class suburb, however is now home to an increasing number of young families and first home buyers.