Mastiff Adoption in Ontario: Mastiff Puppies for Sale in Ontario

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!

Bucky

Mastiff

Male, 5 mos

Kingston, ON

Size

(when grown) Large 61-100 lbs (28-45 kg)

Details

Story

Meet Bucky!Joined us in: April 2026 About Bucky:• Weighs 17.5kg• A friendly, affectionate three-legged pup who doesn’t let anything slow him down!• A social butterfly who LOVES people and is always excited to say hello.• A playful, active boy who enjoys sticks, games, and having fun.• A cuddly companion who also appreciates cozy naps after playtime.• A happy, energetic puppy with lots of love to give.His perfect match:• A first-time owner looking for a fun, loving, and resilient companion.• A home that can keep up with his playful energy and provide regular activity.• A family with children could be a great fit, though supervision is recommended as he can be a bit mouthy.• May do well with another dog; unknown with cats.Some extra facts about Bucky:• Has three legs but gets around great and lives life to the fullest!• Knows “sit” and “stay” — a smart boy with a good foundation.• Crate trained and doing well, and still working on house training.• Very people-oriented and thrives on attention and interaction.• A joyful, resilient pup who brings energy and smiles wherever he goes.In short:Bucky is a playful, affectionate, and inspiring little guy who proves that nothing can hold him back. With some continued training and lots of love, he’ll be a fun, loyal, and heartwarming companion in his forever home.

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Thor

Mastiff/American Bulldog

Male, Adult

Keswick, ON

Size

(when grown) -

Details

Story

Hello there! My name is Thor, Male - neuteredMastiff x American Bulldog MixApprox. 1 year, 11 months oldI'm a big, lovable marshmallow wrapped in an even bigger package. My heart is as large as my frame, and I'm eager to share all the love I have with my forever family. I tend to form strong attachments to my favourite individuals, protecting them from unknowns though I am focused on establishing positive boundaries with the help of my shelter friends. When it comes to people, I'm friendly but can get a little nervous, especially around sudden movements. I thrive best with slow and gentle introductions. Once I feel comfortable, I transform into your classic wiggle bug, ready to make friends and soak up all the affection you have to offer.I enjoy my meals at a normal pace, but what really gets my tail wagging is praise, treats, and spending time with people. I'm highly motivated by love and snacks, which makes training and bonding with me a rewarding experience. I can become protective over toys, so I would do best in a trade-off situation or with gradually introduced toys once I'm settled into my new home. Too much excitement too quickly can be overwhelming for me.I'm still working on my basic training, which means we can learn together. With your guidance and a few tasty treats, I'm sure to pick up on commands and become the well-mannered companion you're searching for.Given my energy and size, I would thrive in a quiet home without young children-preferably with kids aged 12 years or older. I can be selective with doggy friends, but with a slow introduction, I may have the potential to socialize successfully. I do have a prey drive towards cats and would require a home without feline friends.If you're looking for a gentle giant who will fill your home with love and laughter, I'm your guy. Primary Color: Black Brindle Secondary Color: Black Brindle Weight: 42.001 Age: 2yrs 0mths 1wks

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Humphrey

Mastiff

Male, 7 mos

Kingston, ON

Size

(when grown) Med. 26-60 lbs (12-27 kg)

Details

Good with kids, Good with dogs,

Story

Hi, I'm Humphrey! I'm a sweet young pup who loves to snuggle and play. You may notice my skin looks a little funky. I'm working closely with my dogter to manage my skin health. I've made great improvements but we're still working on determining the root cause. MI, Mastiff Mix approx 50lbs EST DOB: Sept 2025

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Noelle

Mastiff

Female, 4 yrs

London, ON

Size

(when grown) Large 61-100 lbs (28-45 kg)

Details

Good with kids, Not good with dogs, Not good with cats, Needs experienced adopter, House-trained,

Story

Re-introducing Noelle! Noelle Fostered in London, On Vaccinated & Spayed & Microchipped Adoption Fee: $500 Mastiff Mix (our best guess) I come with 30 days of free Pet Insurance Hi, I’m Noelle! I’m about 4 years old, and I’m a Mastiff mix who started life as a stray—but thankfully, I was rescued. I’ve been waiting over a year for my perfect forever home, and I think it’s finally my time to tell the world about myself since I've been introduced last. I love going for walks and car rides, but most of all, I adore my people. I’m happiest right by your side (or on your lap, if you’ll let me!). I’m gentle, affectionate, and wonderful with kids I’ve had more stress in my life than a girl like me deserves, so sometimes I can be a bit reactive. The good news is I’ve made amazing progress with my foster family and my friends at Holy Sit Training. I usually walk really well—especially if you bring treats (hint hint!) I am officially Heartworm negative!! which now allows me to get my zoomies out and make you laugh Every now and then, things like certain dogs, motorcycles, or other wheeled vehicles can make me anxious. When that happens, I might jump around or try to chase, so I’ll need someone strong and confident to help guide me—I’m about 80 lbs, after all! I’m very food-motivated and eager to please, which makes training fun and rewarding. I do have a high prey drive (skunks beware) , and while I’m curious about the resident cat in my foster home, she’s not too interested in being my friend… although we’ve been caught almost snuggling once. I’d love a home with a fenced yard (at least 4 feet—I can leap like a ballerina!). Most importantly, I’m looking for someone patient and experienced who can continue helping me grow with structure and training. In return, you’ll get the most loving, loyal cuddle bug you’ve ever met. I just know my perfect person is out there—could it be you? -Noelle BSDRO Foster Dog XOXO

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Priscilla

Mastiff

Female, 6 yrs 3 mos

Toronto, ON

Size

(when grown) Large 61-100 lbs (28-45 kg)

Details

House-trained,

Story

Meet Priscilla, queen of the dog park! Priscilla is such a cutie and just the sweetest girl. She has a curious spirit, a love for treats and has already shown herself to be an affectionate and eager-to-please dog! She always gets excited to see our volunteers and will greet them with her whole body wagging, eager for some attention and maybe a tasty snack or two. On walks, Priscilla is excited to explore and does well when walked at her pace. While she’s confident enough to explore quieter areas, she can get a little spooked by busy or high-traffic zones, but she settles down quickly once she’s in a calmer environment. She’s a quick learner, and she comes right to you when called, especially if there’s a treat involved. Priscilla really enjoys spending time outside, whether walking, playing or simply people-watching. She just enjoys being in the moment! When it’s time to head back, she’s easy to return back home and will happily go back inside for a good petting session. Priscilla is a friendly and sweet-natured dog who thrives on companionship. She will need a patient family that can continue to build her confidence and help her adjust to her new routine at her own pace. She will soon blossom into the loving, loyal companion she’s meant to be. Come say hi to Priscilla today!

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Mastiff

Male, 5 yrs 11 mos

Toronto, ON

Size

(when grown) X-Large 101 lbs (46 kg) or more

Details

House-trained,

Story

HK is a big, goofy 100-pound sweetheart who truly believes he’s a lap dog! This gentle giant has a heart as big as his paws and is always ready to make you smile with his silly antics and affectionate personality. HK loves spending time with his people — he’ll lean right in for cuddles and happily soak up all the love you have to offer. HK’s favorite things? Treats, exploring new places, and being your #1 sidekick. He enjoys going for walks and exploring the world, though due to his size and strength, he’ll need someone comfortable handling a large dog. HK is currently working on his leash manners and learning to stay calm when he spots other dogs. With ongoing positive reinforcement training, he’s making great progress and showing that he’s eager to learn! If you’re looking for a loyal, loving best friend who’ll fill your life with laughter (and maybe take up a bit of space on the couch), HK is your guy!

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

Mastiff puppies and dogs in Ontario

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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!

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Mastiff puppies and dogs in Ontario cities

Mastiff shelters & rescues in Ontario

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Mastiff puppies and dogs in Ontario

Jump to:

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!

Search for a Mastiff puppy or dog

Mastiff puppies and dogs in Ontario cities

Mastiff shelters & rescues in Ontario

Looking for a specific shelter or rescue?

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

Mastiff information

Mastiff basics