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!

Tuna

Mastiff

Female, 2 yrs 2 mos

Kingston, ON

Size

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

Details

Story

Meet Tuna! Joined us in: January 2025About Tuna:• A sweet, affectionate girl who loves attention and being around her people.• Playful and energetic — she’d love a dog friend to run and play with!• Knows “sit” and “paw” — a great start and ready to keep learning.• Can be a bit mischievous if left alone too long (she just misses you!).Her perfect match:• A home that can continue her basic training and provide structure.• A first-time owner ready for a fun, active companion.• Would do well with another dog and could potentially live with a cat.• Someone who can give her enough exercise and companionship to keep her happy and engaged.Some extra facts about Tuna:• Thrives on attention and interaction with her humans.• Would benefit from enrichment and routine to help curb boredom.• A loving, playful girl with lots of potential.In short:Tuna is a fun-loving, affectionate girl who’s ready to learn and play her way into your heart. With the right balance of activity, training, and love, she’ll make a wonderful companion!

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Beth

Mastiff/Cane Corso

Female, 1 yr

London, ON

Size

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

Details

Good with kids, Good with dogs, Good with cats, House-trained,

Story

Beth 1 year old, Mastiff Mix Fostered in London, On Vaccinated & Spayed Microchipped Good with dogs, cats, kids Adoption Fee: $700 Beth is a one-year-old princess with a puppy heart and a deep, joyful love for life and the people in it. She’s the kind of girl who lights up the moment you walk through the door — tail wagging, eyes sparkling, and ready to remind you exactly where the couch is… because together time is her favorite time. Beth is high energy and playful, but she’s just as passionate about her snuggles. One minute she’s chasing a ball, proudly parading around with the biggest stick she can find, or watching squirrels from the yard or window… and the next, she’s curled up beside you for a serious nap. She’s a true couch-and-bed girl who lovingly claims her favorite blankets and pillows — but always makes room for her humans and dog friends! This sweet girl adores attention and companionship. She’ll happily follow you from room to room just to be near her people. She enjoys sunny spots, open windows, outdoor adventures, and simply being part of the day’s rhythm. Beth is social and gentle-natured with zero prey drive — she loves cats, quickly bonded with her foster dog brothers, and is wonderful with kids. She lives to eat (and eats to live!), is fully house trained, and fits beautifully into a home routine. Her days are filled with toys, zoomies, sock-stealing missions, TV cuddles, and gentle kisses. Smart and eager to please, Beth is well trained and loves to keep learning. She’ll offer her paw to show affection — and, if we’re being honest, to politely request a cookie too. Beth is in care through no fault of her own — because sometimes life happens. What she’s hoping for now is a forever family who will match her love, loyalty, and enthusiasm. A family who will give her the support, playtime, encouragement, and cuddles she deserves as she grows into her very best self.

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Oscar

Mastiff

Male, 3 yrs

Hamilton, ON

Size

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

Details

Needs experienced adopter, House-trained,

Story

Oscar is a handsome three-year-old Mastiff cross with a big body and an even bigger heart. This lovable giant has quickly become a staff favorite thanks to his sweet nature, eagerness to please, and calm presence in his kennel. Despite his size, Oscar is a gentle soul who enjoys spending time with people and thrives on connection and positive interaction. Oscar is a medium-energy dog with short bursts of playful enthusiasm —especially when toys are involved! He absolutely loves playtime and is easy to redirect, making him a great candidate for continued training. He’s a smart boy who responds well to guidance and is already showing that he has the potential to become a well-mannered, balanced companion with the right structure in place. Due to his size, strength, and current lack of manners, Oscar is looking for a home with large-breed experience and a confident, physically capable handler. He doesn’t quite realize how big he is, so ongoing positive reinforcement training will be key to helping him learn boundaries and polite behaviors. Enrolling him in training classes is strongly recommended and will set him up for success. Oscar does show some reactivity toward other dogs, particularly males that react to him. However, his behavior is manageable with the right approach. He would benefit from a home committed to maintaining safe distances, using high-value rewards to build positive associations, and consistently working on obedience while keeping him under threshold. With patience, structure, and continued guidance, Oscar has great potential to make progress in this area. Because of his size and strength, a home without young children is recommended. Oscar will also need daily physical exercise and mental enrichment to keep him happy and fulfilled. The good news is that he settles well in his kennel and may do very well with crate training in his future home. Oscar is a sweet, intelligent dog who is ready to thrive with the right match. With consistency, training, and lots of love, he has all the makings of a loyal, well-balanced companion. Please complete an adoption application: https://www.hamilton.ca/home-neighbourhood/animals-pets/adopt-or-foster-pet/adoptions Animal adoptions and viewing are by appointment only. This allows our Adoption Staff to spend quality time with each potential home to ensure the most successful matches are made between the animals and their new families. *Please note: we only adopt within Ontario

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Max

Mastiff/St. Bernard

Male, Young

Keswick, ON

Size

(when grown) -

Details

Story

Hi, my name is Max, Male - neuteredSt. Bernard x Mastiff MixApprox. 1 year, 10 months oldI am hoping to find my forever home soon. I've been the longest resident here, having arrived in April 2025 as a transfer to reach a new audience of potential adopters. Despite my efforts to charm everyone with my friendly nature, I've been overlooked. I'm determined to find the perfect family who will appreciate my unique personality and quirks.When it comes to meeting new people, I am generally friendly but can be a bit cautious and selective. I thrive in the company of adult humans and enjoy their companionship. However, I must admit that I'm not a fan of children, so it's best for me to be in a home without little ones to ensure everyone's comfort and happiness.I have a few key motivators that bring out the best in me: toys, treats, people, and praise. I love a tasty snack, but moderation is key to keeping me healthy and happy. While I've mastered basic obedience, I still have a big puppy demeanor that sometimes shows in my leash skills. I'm known for creating my own symphony by flipping my dish around and pulling the stuffing out of plush toys-what can I say, I'm a musician at heart!I long to be the King of my castle. When it comes to other dogs, I am quite selective, but with time and proper introductions, I might slowly warm up to playdates. However, I would truly thrive in a home where I can be the solo pet, soaking up all the love and attention. I must confess, I'm not fond of furry felines, so a cat-free home is essential.If you're looking for a loyal, fun-loving companion who will fill your home with joy and laughter, I might just be the perfect match for you. Primary Color: White Secondary Color: Brindle Weight: 42.004 Age: 1yrs 11mths 1wks

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London

Mastiff/Boxer

Female, 3 yrs 1 mo

Guelph, ON

Size

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

Details

Story

Hello! My name is London!I`m a fun and loving girl! I am snuggly and affectionate. I love treats and toys, which makes training a blast! I sometimes get excited and like to grab sleeves with my mouth. I thought that was fun but apparently humans don`t enjoy it as much as I do. No worries though, I`m super smart and doing well with training - I`m learning about other fun things to do instead. If you love cuddling, playing and snoring, I am definitely the girl for you!MY IDEAL HOME INVOLVES…CHILDREN: Teenagers may be ok. No young kids given my mouthing can sometimes be hard.OTHER DOGS: I don`t seem to enjoy the company of other dogs and I`m looking to be the only dog.CATS: Potentially, with cat experienced and confident around dogs.FIRST-TIME DOG OWNERS: I would do best with someone who has dog experience.FENCED-IN YARD: Required.HOUSING ENVIRONMENT: Any with yard.SOMEONE HOME MOST OF THE DAY: Not necessarily.SOME OTHER THINGS TO KNOW ABOUT ME…ACTIVITY LEVEL: Medium.HOUSE-TRAINED: Yes.If you think I could be a good match for your home, click the “Adopt Me” button to apply!FOSTER ME! I’m excited to be selected as part of the Paisley Project and I’m looking for a foster home! If your home environment matches what I’m looking for based on the information above, please consider applying to foster me by copying and pasting the following link to fill out the questionnaire: https://guelphhumane.ca/wp-admin/admin-ajax.php?action=frm_forms_preview&form=7y88o.The Paisley Project aims to match selected, long-stay animals at GHS with fosters that can provide a home that gradually introduces them to the everyday experiences of life as a pet. Fosters will offer the routine, structure and stability needed to help get animals ready for their new family. Learn more at https://guelphhumane.ca/the-paisley-project/.

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Priscilla

Mastiff

Female, 6 yrs 2 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 puppies and dogs 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