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Mastiff puppies and dogs in Ontario

Looking for a Mastiff puppy or dog in Ontario? Adopt a Pet can help you find an adorable Mastiff near you.

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Adopt a Mastiff near you in Ontario

Below are our newest added Mastiffs available for adoption in Ontario. To see more adoptable Mastiffs in Ontario, use the search tool below to enter specific criteria!
Photo of Big Time

Big Time

Mastiff

Male, Young
Woodstock, ON
Size
(when grown) X-Large 101 lbs (46 kg) or more
Details
Good with kids, Good with dogs, House-trained,
Story
Big Time is the sweetest, kindest dog. Hes very big, about 165lbs. He has been trained in all basic obedience and is very attentive. He loves to lay around and go for short walks, when its not too hot. It is important that you know challenges of having a dog as big as he is. He has a long tail that's very strong. He loves children, but smaller children will be bumped and knocked over by this clumsy teddy bear. He has always gotten along with other dogs of all kinds, and is quick to submit, instead of looking for trouble. He doesn't do a lot of barking, but may bark at a strange sound if he doesn't know what it is. This is not a guard dog... If you are looking for a big scary guard dog, YOU HAVE THE WRONG GUY. He is sweet and as gentle as he can be, given his size and weight. Feeding Big Time is not cheap. He is a very healthy dog that eats just under 8 cups of food per day (4 in the morning and 4 at night. Big time needs a walk every day, and he needs to be outside twice per day.
Photo of KOJACK

KOJACK

Mastiff

Male, 2 yrs 6 mos
London, ON
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
-
Story
-
Photo of Max

Max

Mastiff/St. Bernard

Male, Young
Keswick, ON
Size
(when grown) -
Details
-
Story
Hi, my name is Max, Male - neuteredMastiff St. Bernard MixApprox. 1 year oldI'm a cheerful and lovable goofball, sometimes blissfully unaware of my size, but in the best possible way. I certainly know how to pose for a treat, though let's be honest-I'm always a sight to behold! I love going for walks and bringing along my favorite stuffed toy for the journey. If you want to play outside, just look at my tail wagging high with excitement! During my time in care, I've had the chance to join doggy play groups, which I absolutely adore. I enjoy the company of my fellow furry friends, although I have yet to meet any feline companions. Primary Color: White Secondary Color: Brindle Weight: 36.005 Age: 1yrs 0mths 3wks
Photo of Morticia

Morticia

Mastiff/Boxer

Female, 5 yrs
Belleville, ON
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
-
Story
Meet Morticia: A 5-Year-Old Mastiff Mix in Need of a Dedicated, Experienced HomeMorticia is a 5-year-old spayed Mastiff mix with significant behavioral challenges. She is not a beginner’s dog. She requires a highly experienced, adult-only adopter who understands fear-based behavior, stress-induced aggression, and the time and patience it takes to earn the trust of a dog with a difficult past.Behavioral Overview:Morticia has exhibited extreme barrier aggression, meaning she reacts with barking, lunging, and visible agitation when confined behind gates, fences, or kennel doors. This behavior is rooted in fear and stress—not aggression for aggression’s sake—but it is serious and must be managed accordingly.She has also shown stress-induced aggression, a common behavior in undersocialized or formerly stray dogs who have not had stable or positive interactions with people. This means that under extreme duress, she may snap or growl as a defensive response. These reactions are not unpredictable, but they must be taken seriously.Current Support & Management:Morticia is currently being supported with Trazodone, a commonly used anti-anxiety medication in shelter environments. Trazodone helps reduce her overall anxiety, allowing her to better tolerate everyday stimuli and interactions. While it has made a positive difference, medication alone is not enough—Morticia requires ongoing behavioral support, structure, and a safe, predictable home environment.What Morticia Needs:Multiple Meet-and-Greets:Morticia will not warm up quickly. Potential adopters should expect to meet her at least two to three times, possibly more, before she begins to show signs of trust or engagement. This process should not be rushed.Adult-Only Home:Morticia cannot be placed in a home with children or teens. Her environment must be calm, quiet, and free from sudden changes, loud noises, or unpredictable behavior.No Other Animals:Morticia has shown discomfort and agitation around other dogs. Given her high level of stress and her tendency toward fear-based reactivity, she must be the only pet in the home.Ongoing Training and Structure:Morticia needs a handler who understands the importance of boundaries, structure, and consistent routines. Positive reinforcement, calm leadership, and professional behavioral support will be key to her long-term success.Who Should Consider Morticia:
Photo of Inara

Inara

Mastiff/Shar Pei

Female, Young
Athens, ON
Size
(when grown) -
Details
Good with kids, Good with dogs,
Story
File #25-085 Current Foster Location: Renfrew, ON *Please note that we do not typically adopt outside of a 2 hour radius from the foster dogs current location* Hi, I'm Inara ! Guess what? I'm finally learning to be the big goofy puppy I was always meant to be! My journey has been more dramatic than a season finale of Grey's Anatomy. Born with Entropion in both eyes, I was in serious pain until the amazing Dr. Julie gave me relief. I had my eyes tacked for now, and the pain is gone! When I get older, closer to a year, Ill have the final surgery to fix them, so Im good for the rest of my life. My adoption contract will cover this and the cost will be paid by these nice Village folks. Before my eye treatment, it was dark and twisty, walking around with my eyes closed because opening them hurt so much. I was a quiet shut down puppy as I didnt feel like playing with all the pain I had. I relied on my doggy friends and my nose to navigate life. But now? I can see! It's like I've a whole new world for me overnight! I LOVE following other dogs, playing with toys, and prancing around on my hilariously oversized paws. To continue building my confidence, I'll need another canine brother or sister. Im not ready to be an only dog in the home yet, as the worlds still a little scary for me, but Im getting there. House training is a work in progress, but I keep my kennel clean and Im doing really well. I only have the odd accident if I get playing and forget I need to go outside. I will also use pee pads inside if needed. My crate used to terrify me, but now we're cool. I dont love it yet, but I understand my foster family will come back and that its a safe place for me while they are gone. Car rides make me nervous but with time I'll improve, I dont get car sick, so thats a bonus! Oh, and heads up - I'm definitely a cuddler who loves the couch, I believe your furniture is our furniture. I love to sleep in bed a night sometimes with my humans and foster fur siblings.not all the time, as my foster momma says I need to learn to love my crate, but she lets me snuggle the odd night here and there. Im a good girl and sleep through, unless I need to wake her up for a piddle outside, which happens from time to time. So, what do you saypick me, choose me, love me? Can I join your family? Please visit our website www.ittakesavillagedogrescue.com to learn more about this amazing dog and to see other available dogs.
Photo of Sebastian

Sebastian

Mastiff/German Shepherd Dog

Male, 3 mos
Woodstock, ON
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
Good with kids, Good with dogs, Good with cats,
Story
Sebastian is one of 11 siblings born on Family Day. He is a typical little puppy.....eat,.play, poop .sleep (maybe not in that order!). He's a pretty laid back guy who loves to run and wrestle his siblings. He will grow into those large dog paws, so some experience with the breeds will be beneficial. He has been dewormed and will be visiting the vet next week for his vaccines and microchip, and will come with a voucher for his neuter done at 6 months, at our vet in Woodstock. To facilitate his neuter surgery, adopters must live with half an hour from Woodstock. His adoption fee is $500. You must be 21 years old to adopt and provide vet and personal references. An application to adopt him can be found on our website www.oxfordcountyanimalrescue.com. Click on Adopt, then Dogs for Adoption and scroll to the bottom of the page. Do not click on his profile or use Autofill as the application will not submit. All applications are reviewed, and if we feel you might be a good fit for him, you will be contacted to arrange a home visit as well as for permission to speak with your vet. Repeated phone calls and emails with not advance your application. We are a volunteer, foster based rescue and there is no opportunity to meet him before an application has been approved. We thankyou for respecting these guidelines

Search for a Mastiff puppy or dog

Use the search tool below to browse adoptable Mastiff puppies and adults Mastiff in Ontario.

Mastiff puppies and dogs in Ontario cities

Mastiff Puppies near me Mastiff in Acton Mastiff in Alliston Mastiff in Almonte Mastiff in Amherstburg Mastiff in Angus Mastiff in Arnprior Mastiff in Aylmer Mastiff in Ayr Mastiff in Azilda Mastiff in Barrie Mastiff in Beamsville Mastiff in Beeton Mastiff in Belleville Mastiff in Binbrook Mastiff in Blenheim Mastiff in Bobcaygeon Mastiff in Bolton Mastiff in Bowmanville Mastiff in Bracebridge Mastiff in Bradford Mastiff in Brantford Mastiff in Brighton Mastiff in Brockville Mastiff in Caledon East Mastiff in Caledonia Mastiff in Campbellford Mastiff in Carleton Place Mastiff in Casselman Mastiff in Chatham Mastiff in Chelmsford Mastiff in Clinton Mastiff in Cobourg Mastiff in Cochrane Mastiff in Collingwood Mastiff in Cornwall Mastiff in Corunna Mastiff in Crystal Beach Mastiff in Deep River Mastiff in Delhi Mastiff in Dorchester Mastiff in Dryden Mastiff in Dunnville Mastiff in Elliot Lake Mastiff in Elmira Mastiff in Embrun Mastiff in Espanola Mastiff in Essex Mastiff in Exeter Mastiff in Fergus Mastiff in Fort Erie Mastiff in Fort Frances Mastiff in Gananoque Mastiff in Georgetown Mastiff in Goderich Mastiff in Gravenhurst Mastiff in Guelph Mastiff in Haileybury Mastiff in Hamilton Mastiff in Hanover Mastiff in Hawkesbury Mastiff in Hearst Mastiff in Huntsville Mastiff in Ingersoll Mastiff in Innisfil Mastiff in Iroquois Falls Mastiff in Kanata Mastiff in Kapuskasing Mastiff in Kemptville Mastiff in Kenora Mastiff in Keswick Mastiff in Kincardine Mastiff in King Mastiff in Kingston Mastiff in Kirkland Lake Mastiff in Kitchener Mastiff in Leamington Mastiff in Lindsay Mastiff in Listowel Mastiff in Lively Mastiff in London Mastiff in Manotick Mastiff in Marathon Mastiff in Meaford Mastiff in Midland Mastiff in Milton Mastiff in Mitchell Mastiff in Mount Albert Mastiff in Mount Forest Mastiff in Napanee Mastiff in Newcastle Mastiff in New Hamburg Mastiff in New Liskeard Mastiff in Niagara Falls Mastiff in Nobleton Mastiff in North Bay Mastiff in Orangeville Mastiff in Orillia Mastiff in Oshawa Mastiff in Ottawa Mastiff in Owen Sound Mastiff in Paris Mastiff in Parry Sound Mastiff in Pembroke Mastiff in Perth Mastiff in Petawawa Mastiff in Peterborough Mastiff in Petrolia Mastiff in Picton Mastiff in Port Colborne Mastiff in Port Dover Mastiff in Port Elgin Mastiff in Port Hope Mastiff in Port Perry Mastiff in Prescott Mastiff in Renfrew Mastiff in Richmond Mastiff in Ridgetown Mastiff in Rockland Mastiff in Rockwood Mastiff in Russell Mastiff in Sarnia Mastiff in Sault Ste. Marie Mastiff in Shelburne Mastiff in Simcoe Mastiff in Smiths Falls Mastiff in Smithville Mastiff in Southampton Mastiff in Stayner Mastiff in St Catharines Mastiff in St George Mastiff in St Marys Mastiff in Stouffville Mastiff in Stratford Mastiff in Strathroy Mastiff in St Thomas Mastiff in Sturgeon Falls Mastiff in Sudbury Mastiff in Sutton West Mastiff in Tavistock Mastiff in Thunder Bay Mastiff in Tilbury Mastiff in Tillsonburg Mastiff in Timmins Mastiff in Toronto Mastiff in Tottenham Mastiff in Uxbridge Mastiff in Vineland Mastiff in Walkerton Mastiff in Wallaceburg Mastiff in Wasaga Beach Mastiff in Waterford Mastiff in Welland Mastiff in Wellesley Mastiff in Windsor Mastiff in Woodstock

Mastiff shelters & rescues in Ontario

There are animal shelters and rescues that focus specifically on finding great homes for Mastiff puppies in Ontario. Browse these Mastiff rescues and shelters below.

Here are a few organizations

Rescue

Oxford County Animal Rescue

789 Dundas Street, Woodstock , ON N4S 1E1

Pet Types: cats, dogs

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Rescue

F.A.B.R Canine Rehabilitation Therapy and Sanctuary

Haldimand County , ON N3Y 4J9

Pet Types: dogs

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Rescue

Pound Dog Rescue

P.O. Box 261, Drumbo , ON N0J 1G0

Pet Types: dogs

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Shelter

London Animal Care Centre

121 pine valley blvd, London , ON N6K 3T6

Pet Types: cats, birds, dogs, rabbits, reptiles, small animals

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Shelter

Guelph Humane Society

500 Wellington Street, West, P.O. Box 684, Guelph , ON N1H 6L3

Pet Types: cats, birds, dogs, farm animals, horses, rabbits, reptiles, small animals

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Rescue

Dog Tales Rescue and Sanctuary

1405 19th Sideroad, King City , ON L7B 1K5

Pet Types: cats, dogs

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Looking for a specific shelter or rescue?

If you're not seeing what you're looking for, try our shelter and rescue search. We have more than 17,000 organizations in our database with furry pals waiting for a new home!

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Want to learn more about adopting a Mastiff puppy or dog ?

We've got all the info you need on adopting and caring for a Mastiff puppy . Check out the links below for everything you ever wanted to know about Mastiff puppies and adults .

Mastiff information

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Where do Mastiffs come from? How many types of Mastiffs are there? From the history of the breed to question about average height, weight and size, brush up on these basic facts about the Mastiff.

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