Heaviest dog breed
- Who
- Unknown
- What
- 77 - 91 kilogram(s)
- When
- 01 January 0001
The heaviest breeds of domestic dog (Canis familiaris) are the Old English mastiff and the St Bernard, with males of both species regularly weighing 77–91 kg (170–200 lb).
In its pre-2009 breed guidelines, the Kennel Club (UK) states that the ideal mastiff should have "a large, powerful, well knit frame", displaying "a combination of grandeur and courage".