You need to find a Glock 21 holster. So, how do you choose the holster that will work the best for you? Well, that depends on how you plan to carry your Glock. If your purpose is to carry concealed for self-defense, you’ll need a holster specifically for concealed carry. If you’re going to carry it as a duty weapon, other holsters will be better suited.

Our choice for the best holster for the Glock 21 is the Mini Slide Holster by Desantis. This diminutive leather belt slide holster is molded for specific firearms. It puts the pistol close to your body for security. There are no retention straps to slow down your draw time, but there is an adjustable retention screw.

What to Consider When Buying a Holster

When purchasing a holster for your Glock 21, you need to consider what you need in a holster and what the various holster types can provide. Do you plan to carry concealed? Think about your wardrobe and determine if you can guarantee concealment.

You might want an inside the waistband (IWB) holster to keep your firearm close at hand, yet ease concealment. Or, depending on your level of activity, you might choose an ankle or belly band holster.

Are you carrying on duty? You’ll need an outside the waistband (OWB) holster, unless your Glock is a backup piece. If you’re involved in serious tactical situations, a leg holster might be ideal.

Another thing to remember is that many holsters are not ambidextrous. This means if you’re right-handed, you need to get a right-handed holster. This applies even when purchasing a shoulder holster or any holster for cross-draw.

General Types of Holsters

  • Semi-permanent belt clips: these mount directly to the grip of your firearm, allowing you to easily carry the pistol without the added bulk of a holster.
  • Outside the Waistband (OWB) holsters: these are worn either on a belt or clipped to the pants, and the gun is not concealed under clothing unless a jacket or long shirt is added.
  • Inside the Waistband (IWB) holsters: these will place the pistol inside the pants and secured by clips to the waistband.
  • Shoulder holster: these are a harness-like holster which allows you to carry your firearm nestled under your off-side arm. This is a cross-draw holster.
  • Belly Bands: these are neoprene bands that fit around the belly with a nylon holster sewn in place. Remember, this may increase your draw time.

Some Things to Keep in Mind

There are several things you need to keep in your thoughts when it’s time to buy a holster for your Glock.

Frame and Barrel Length

Glocks come in a variety of models, and some of them have longer barrels than others. If you are purchasing a closed-end holster, you’ll need to make sure your pistol will fit properly.

Concealed, or Not?

If you will carry your Glock predominantly concealed, you’ll need a holster designed for that purpose. Most of the time, these will be either inside the waistband (IWB) holsters, but shoulder and ankle harnesses work for concealment as well.

If you plan to carry on your side in the open, a belt clip or slide holster will likely work the best for you. Or if your intended purpose is to carry in a tactical situation, you may decide a leg holster or one that can attach to a vest would be the ideal holster for you.

Your Dominant Hand

If you’re not ambidextrous, and most of us aren’t, you’ll want to make sure to purchase the holster that’s right- or left-handed for your strong side. Of course, if you want to go cross-draw or shoulder holster, the same applies; if you want to draw with your right hand, a right-handed shoulder harness is needed (the gun will be below your left arm).

Retention and Draw Speed

If you’re a very active person, or if you intend to carry your Glock in the line of duty, you’ll want to have some type of retention guaranteeing your pistol is secure in the holster. This might include a retention strap or thumb break (Level 1 retention) or a retention screw to control how tight the firearm sits in the holster. There are also Level 2 and Level 3 retention holsters for those in law enforcement or military. These help prevent an assailant from removing the firearm from the holster.

Getting Down to the Nitty Gritty

Now that you have an idea of what type of holster you’re looking for, let’s get into some more specific makes and models. We’ll go over each one and present the pros and the cons so you can see them for yourself.

Paddle Holster-Straight Drop by Comp-Tec

Paddle Holster-Straight Drop by Comp-TecyThis polymer holster is the best-selling outside the waistband (OWB) holster for Comp-Tec, and it’s IDPA (International Defensive Pistol Association) certified. It’s been used by several IDPA champions.

It’s worn hooked over the pants or belt at the 3 o’clock position. This allows you to wear with or without a belt. But, the paddle may be uncomfortable for those who are thin with bony hips.

There is no retention strap or thumb break on these holsters, and it doesn’t appear to have a user-adjustable retention screw. It’s also fixed cant (carry angle), which means it can’t be adjusted for height or angle.

Each holster is molded to a specific firearm, and they’re also not ambidextrous. So, you’ll want to make certain you order the correct make and side when you purchase one. This holster runs just over $60.

The Defender Leather IWB Holster by Relentless Tactical

This is a leather holster designed to be worn inside the waistband (IWB). It’s somewhat formed to specific models, but has a wide range of applications. The Defender is a handmade holster crafted from bull leather, designed to last a lifetime.

There is no retention strap on this holster, and retention relies on pistol fit and weight. But, being inside the pants, it allows you to carry concealed, providing your shirt or coat covers the weapon.

This is not an ambidextrous holster, so you’ll want to use caution when ordering one online. Each Defender is backed by Relentless Tactical’s lifetime warranty, giving you the confidence to carry this holster on a daily basis. It’s priced at $40.

OWB Belt Holster with Magazine Pouch by Barsony Holsters and Belts

OWB Belt Holster with Magazine Pouch by Barsony Holsters and BeltsThe outside the waistband (OWB) holster is made of Cordura nylon, and features a spare magazine pouch at the front of the holster. The sturdy metal belt clip allows use on belts up to 1.75 inches.

This holster has waterproof closed-cell padding and the tip is sealed, preventing water or dirt from working their way up your barrel. It’s not ambidextrous, so make sure to purchase the one for your strong side.

It also comes with an adjustable retention strap and thumb break, so you can adjust to fit your pistol perfectly. Keep in mind that any retention strap may increase your draw time. This holster is priced at just over $20.

Mini Slide Holster by Desantis

Mini Slide Holster by DesantisThis leather holster by Desantis is made of durable saddle leather. There are two slots to slide this thin pancake holster onto any belt up to 1 and ¾ inches wide.

The Mini Slide holster is molded to fit specific models, and it does have a wide range of applications. The bottom is open to accommodate different sized barrels.

There is an adjustable retention screw, but no strap or thumb break. You’ll get a quick, seamless draw from this holster, which is designed with a muzzle back cant (carry angle). Because of the belt slots, the cant is not adjustable.

This holster is priced around $45.

SERPA Level 3 Auto Lock Duty Rig by Blackhawk!

This is an outside the waistband (OWB) holster designed for law enforcement, security, or military. It’s made of molded polymer and has a sight channel to protect your firearm’s important features. But, it may not work if aftermarket sights are installed, and doesn’t provide space for a mounted laser sight or tactical light.

The passive retention is achieved by holstering the gun; you’ll hear an audible ‘click’ when it’s properly seated. This retention is adjustable by using the screw. In addition, there’s a finger button in a natural position to enable a proper grip when drawing. The button releases easily, yet is difficult for an assailant to release.

There is also a thumb-operated pivot guard for additional security. Both the finger release and the thumb pivot must be triggered in order to draw, so if you buy this type of holster, make sure to practice with it so drawing becomes natural.

The holster secures to belt by way of belt slots at the top, and is not adjustable for height or cant (carry angle). Size 13 is what will fit a Glock 21, and it’s pricey at $100.

Our Final Pick

For the price and durability, we’ve chosen the Mini Slide Holster by Desantis. This holster can be used for concealment as well as open carry, and comes with an adjustable retention screw, somewhat unique in leather holsters.

Our Pick
 Mini Slide Holster by Desantis
Best Holster for Glock 21Mini Slide Holster by Desantis

Premium saddle leather, double seams and a highly detailed molded fit, make this exposed muzzle, tight fitting, two-slot holster a great choice for your favorite pistol. It features an adjustable-tension device. Belt slots are 1 3/4" wide.

Buy now

There’s no thumb break or complicated retention system to remember, and this pancake holster offers a quick draw while keeping your weapon snug to your body. It can only be worn on a belt, but your Glock 21 is valuable, and the added security of a belt slide holster is excellent.

The cant isn’t adjustable, but it’s not a straight drop. Instead, your pistol will ride muzzle-back, putting it into excellent position for drawing for defense purposes.

The Mini Slide Holster by Desantis is an excellent all-around holster for the price.