Best Dog Collars for Mastiffs | Strong, Secure, Custom Fit

The best collar for a Mastiff is wide, strong, and custom-fit to prevent slipping and reduce pressure on the neck. Choose Biothane®, leather, or martingale styles with reinforced stitching and adjustability. Most adult Mastiffs need 22–30″ collars; puppies grow fast, so check size often.

If you’re searching for the best collar for your Mastiff, you need one that’s strong, secure, and tailored to fit a giant breed. The right collar for a Mastiff is 1.5 inches wide, reinforced with durable hardware, and made from materials that won’t rub or irritate their skin. 

Flat collars work well for everyday ID, but martingales offer gentle slip-proof control, especially helpful for those sudden lunges toward squirrels. 

For the heavy pullers, a martingale or wide leather collar with a handle gives you security without sacrificing comfort. 

At Mimi Green, we design custom-fit collars that actually accommodate Mastiffs’ necks. We even test all of our collars on our own Mastiff – pictured here!

Our waterproof Biothane®, leather, and velvet collars are all handmade to order in the USA, and we test our gear on real dogs (including 120-lb pups) to ensure it holds up to the challenge. 

You can even add embroidered names or engraved buckles for a personalized touch that’s as strong as it is stylish.

Want the deep dive? If you’re curious about sizing tips, collar types, or how to choose between a collar and harness, we’ve got everything covered below. If all you need is a safe, beautiful collar that won’t fall apart after a few walks? We’ve got that handled, too.

Why Mastiffs Need Special Collars

Featured Product: 1.5 Inch Wide Personalized Blue an White Laminated Dog Collar ‘Capri’

Mastiffs are gentle giants with massive necks and strong frames. Their collars must balance comfort, control, and durability, especially for pulling or training.

A standard “XL” collar? Often not even close. Adult Mastiffs typically measure between 22–30” around the neck, with some stretching past 38”. 

Most off-the-shelf options top out too soon or aren’t wide enough to distribute pressure safely. When collars sit too tight or too narrow, it leads to chafing, especially around skin folds or under the buckle.

And while they’re big, Mastiffs can be surprisingly sensitive. Their short coats don’t offer much protection against scratchy edges or clunky hardware. 

That’s why smooth finishes, reinforced stitching, and soft-yet-strong materials (like Biothane® or premium leather) aren’t just preferences, they’re must-haves.

Mastiffs also grow slowly and steadily for up to three years. Puppies may outgrow their gear several times, which makes adjustable collars and regular fit checks essential if you want to avoid discomfort or dangerous slip-offs.

Best Collar Styles for Mastiffs

Featured Product: Leather Martingale Dog Collar with ID Riveted Nameplate

Not all collars are created equal for giant breeds. These top picks provide control without discomfort, even for hard pullers.

Martingale Collars – Gentle Slip Control

For Mastiffs who back out of flat collars or need a little extra guidance on leash, martingales offer a safe, non-choking way to prevent escapes. Unlike choke chains, martingales tighten just enough to stay secure, without crushing a thick neck.

Our martingales come in reflective nylon, and waterproof Biothane®. Each one is handmade and reinforced, because we know “gentle giant” doesn’t always mean gentle on gear.

Waterproof Biothane® Collars – All-Terrain Tough

Mud, drool, snow, repeat. That’s life with a Mastiff. Biothane® looks like leather but wipes clean with soap and water. It’s stink-proof, durable, and stays flexible, even after long hikes or messy play.

These collars are a favorite for dogs who wear their gear all day, and for owners who want something low-maintenance that still feels luxurious.

Leather Collars – Classic & Comfortable

Nothing softens into your dog’s shape like real leather. For Mastiffs, wide leather collars distribute pressure evenly and look downright regal doing it.

Each Mimi Green leather collar is available with optional engraved buckles or matching leashes. 

They take a little extra care, think conditioner, not the washing machine, but they’re a timeless investment in both comfort and style.

What Size Collar Does a Mastiff Need?

Most adult Mastiffs need a collar between 22–30 inches. Always measure the neck before buying, especially for puppies or growing dogs.

Don’t guess based on weight. 

Neck size can vary dramatically, even between littermates. 

• Measure the widest part of your dog’s neck, or their head if larger, using a soft tape.
• Ensure two fingers can slide between the collar and your dog’s neck when worn.
• For puppies, begin with an 12–16” collar and regularly check the fit due to rapid growth.

That’s why Mimi Green offers adjustable sizing and custom-fit collars, because no one-size-fits-all product can really fit your big, beautiful dog.

Collar vs Harness for Mastiffs – What’s Better?

While a collar is a must for ID and tags, many Mastiffs benefit from a harness, especially if they’re leash-pullers, recovering from an injury, or tend to back out of collars. But not all harnesses are a good fit for wide, muscular dogs.

Mimi Green’s step-in harnesses are a favorite for Mastiffs with broad chests. Unlike front-clip styles (which often shift off-center and cause leg chafing), our designs stay balanced and secure. We also avoid rough webbing and instead offer all our harnesses in the same soft, stylish materials as our collars, so you can match function with fashion.

And since we make everything to order, you can customize both your collar and harness to fit your Mastiff’s size, shape, and style perfectly.

Training a Mastiff? Read This First

Mastiffs are smart, loyal, and eager to please, but they’re also powerful and protective. When training, your tools should guide, not punish. A martingale collar is often the best place to start. It gently tightens when your dog pulls, offering feedback without pressure on the throat.

Martingales – Safe for Everyday Training

Martingales are ideal for leash work and walk-time manners. They tighten enough to prevent backing out but loosen immediately once tension stops. For Mastiffs, the key is a wide band (1.5” or more) to distribute that tension evenly. 

Mimi Green’s martingales come in Biothane®, velvet, and nylon webbing, each reinforced to handle a strong dog’s pull.

5 Collar Fit Worries (and How to Solve Them)

Mastiff parents worry about fit, safety, and strength. Here’s how to fix those concerns confidently.

• Will it fit? Most “XL” collars max out around 26”, but many Mastiffs measure up to 38”. That’s why Mimi Green offers custom sizing. No awkward gapping, no tight pinching.
• Will it chafe? Choose materials that are smooth but durable. Biothane®, soft leather, or velvet collars minimize friction, even around folds and jowls. Avoid stiff edges or poorly finished seams.
• Will it break? You need reinforced stitching and industrial-strength hardware. Our hybrid buckles (military-grade plastic plus metal) outperform traditional metals because they don’t rely on delicate springs.
• Can it be chewed off? If your dog can chew it, it probably doesn’t fit right. Properly fitted collars sit high enough that they’re out of reach. And we never recommend carabiner or climbing rope collars, they’re not designed for actual dogs.
• Is it safe to leave on all day? Martingales should be removed when your dog is unsupervised. Flat collars, if fitted properly and made with strong, non-irritating materials, are generally safe for everyday wear.

How to Clean, Maintain, and Replace Your Mastiff’s Collar

With a breed this big, collars see wear fast. Mud, drool, food, and general goofiness all take a toll, so your Mastiff’s gear needs regular care.

• Biothane® and waterproof styles: Just rinse and wipe with soap and water. These are perfect for low-maintenance families.
• Leather collars: Use a gentle conditioner every few months. Keep them dry and away from direct sunlight.
• Nylon collars: Hand-wash in cool water and air-dry. These are durable but benefit from a little extra love.

When to replace: Check for frayed stitching, cracked hardware, or a loose fit. Puppies? Expect to replace every few months. Adults? Every 6–12 months depending on wear.

Matching Leash + Collar Combos for the Full Setup

Featured Product: Leather Martingale Dog Collar w/ Engraved Riveted Nameplate

Big dogs need sturdy, stylish sets that can handle their momentum and showcase their personality.

A strong collar does half the work, the leash does the rest. For Mastiffs, that means a leash with:

• A secure, heavy-duty clasp
• 4–6 feet in length (no retractables)
• Comfortable handles for your hands

At Mimi Green, you can customize your leash to match your collar, whether that’s a waterproof Biothane® martingale or a leather flat collar with engraved nameplate. 

Add embroidered names, poop bag holders, or key fobs to complete the look.

Because let’s be honest, when your dog is the size of a small pony, it helps if their accessories at least look like they’re under control.

FAQs About Mastiff Collars

Quick answers to your top questions about collars for large dogs like Mastiffs.

• What size collar does a Mastiff need? Most adult Mastiffs wear collars between 22–30 inches. Always measure your dog’s neck with a soft tape, and choose a collar that offers a snug-but-comfortable fit with room to adjust.
• Can a Mastiff wear a martingale? Yes. Martingales are one of the best options for Mastiffs who tend to pull or back out of traditional collars. They tighten just enough to prevent escape, without causing harm.
• Best collar for big pullers? A martingale is a safe, daily-use tool that offers gentle correction. For stronger guidance, consider a training setup with a step-in harness or, under trainer guidance, a prong collar.

Final Checklist for Your Mastiff Gear

Everything you need to walk, train, and enjoy life with your Mastiff safely and in style.

• ✅ Custom-fit collar (Biothane®, Leather, or Martingale)
• ✅ Reinforced leash (not retractable)
• ✅ Step-in harness for backup or daily walks
• ✅ Embroidered or engraved ID
• ✅ Poop bag holder & waste pouch
• ✅ Measuring tape for growth check-ins

Whether you’re heading out for a weekend hike or a quick walk around the block, having reliable gear means less stress for you, and more tail wags from your pup.

Why Choose Mimi Green for Your Mastiff?

Featured Product: Martingale Mermaid Glitter Dog Collar w/ optional Personalization

You don’t just need a big collar, you need one that fits, lasts, and reflects your dog’s personality. That’s what we make, right here in the USA.

Most “big dog” collars on the market aren’t designed for real-life use. They chafe, slip off, or fall apart under pressure. At Mimi Green, we hand-make each collar to order, using materials like waterproof Biothane®, soft full-grain leather, and heavy-duty hardware that’s tested on real 120-lb dogs.

Plus, we don’t just scale up small dog collars. Our gear is tailored for giant breeds. 

We offer neck sizes up to 38”, wide styles to protect your pup’s neck, and matching harnesses that actually stay in place on deep-chested dogs. Add a custom engraved buckle or embroidery, and your dog’s collar becomes as unique as they are.

When your dog is this big, “good enough” doesn’t cut it. Mimi Green helps you find the paw-fect fit that’s stylish, secure, and made with love.

Find the Right Fit, Without Compromise

Mastiffs don’t just need bigger collars, they need better ones. 

Whether you’re managing a powerful puller, outfitting a fast-growing puppy, or simply looking for a collar that won’t chafe or fall apart, we’ve got you.

At Mimi Green, we build gear that’s made to last, handmade to order, right here in the USA.

From waterproof Biothane® collars that rinse clean after muddy walks, to custom leather martingales with engraved buckles, everything we offer is designed for durability, comfort, and personal style.

Ready to find a collar that actually fits your Mastiff?

Browse our collection of wide, custom-sized collars built specifically for big dogs, no guessing, no slipping, no compromise.

👉 Shop Custom Mastiff Collars Now

Still unsure about size or style? Our team is always here to help with fit advice, matching harnesses, or collar recommendations based on your dog’s needs. 

Because your dog deserves more than a generic collar, they deserve one made just for them.