Used 2021 GMC Sierra 1500 for Sale nearAjax, ON

How much does the 2021 GMC Sierra 1500 cost?

Prices have softened 14.00% compared to this time last year, making it a favourable time to shop this model year.

There are 602 listings available, which gives you a solid amount of inventory to compare.

Is the 2021 GMC Sierra 1500 a good car?

Yes — the 2021 GMC Sierra 1500 earns a 4.9/5 user rating and a 5.7/10 expert rating. The standout strength is Performance at 9/10.

Owners consistently praise its luxurious features, exceptional engine performance, advanced technology, and comfortable interior. That lines up with the Sierra 1500’s role as a full-size pickup that leans into a more upscale presentation and distinctive styling rather than a complete reinvention.

For you, that means it makes the most sense if you want a familiar truck formula with premium touches and strong capability. With 34.2% of listings marked as good or great deals, the market offers some room to shop carefully.

Is the 2021 GMC Sierra 1500 reliable?

Owners rate it 4.9/5, a strong signal of long-term satisfaction.

Reviewers describe it as a truck they feel good about owning over time, with comments pointing to dependable performance, strong value, and a generally trouble-free experience. The expert assessment also highlights that the Sierra remains fundamentally appealing, with a powertrain that feels well matched to the truck’s mission and a 10-speed automatic that is adept at keeping the engine in its torque band.

The diesel option is also presented as a particularly strong value, which can help if you want a capable truck without stretching into the highest trims. For used buyers, the main long-term ownership risk is less about basic durability and more about paying extra for the features you want.

What should I look for when buying a used 2021 GMC Sierra 1500?

Key things to evaluate:

• Trim level: The Sierra’s styling and upscale Denali trim level are key differentiators, while the AT4 adds off-road-ready hardware such as a suspension lift, skid plates, a locking rear differential, and unique design details. Base versions can feel sparse, and some desirable equipment is tied to higher trims or packages.
• Powertrain: The available Duramax 3.0-litre turbodiesel six-cylinder is the standout engine here, with strong torque and a 10-speed automatic transmission. It is also described as a bargain relative to diesel options from some rivals.
• Safety package: Forward collision warning, front pedestrian braking, and automatic emergency braking are optional, while blind-spot warning and rear cross-traffic warning are included on Denali and optional on other trims. Lane-departure warning, lane-keeping assistance, and a Safety Alert Seat are also available depending on trim.
• Infotainment: You can get either a 7-inch or 8-inch touchscreen, and wireless Apple CarPlay and Android Auto come standard. The Sierra also offers Bluetooth, SiriusXM satellite radio, a 4G LTE WiFi hotspot, and optional navigation.
• Fuel efficiency: The Duramax diesel is rated at 9.1 L/100 km in combined driving, and the test truck averaged 11.1 L/100 km in mixed conditions.

Which 2021 GMC Sierra 1500 trim should I buy?

The 2021 GMC Sierra 1500 is offered in 4 trim levels: Elevation, SLT, AT4, and Denali.

Here's the short version:

• Elevation: This is the trim most buyers should strongly consider if you want to keep costs in check while still getting a custom appearance and access to a wide range of options. It is the best-value path if you want to avoid the Sierra’s tendency to climb quickly in price.
• SLT: This trim makes sense if you want a more upscale feel and access to more equipment, including available adaptive cruise control. It is a good middle ground if you want comfort and convenience without jumping straight to the top end.
• AT4: Choose this if you want the off-road-ready version with a factory-installed suspension lift, skid plates, a locking rear differential, and rugged styling. It suits you best if you want capability and a more adventurous look.
• Denali: This is the luxury-focused choice, with the most premium presentation and features such as blind-spot warning and rear cross-traffic warning. It is the right pick if you want the Sierra’s most upscale experience.

The safety package is uneven across the range, so it is worth checking exactly which driver-assistance features are included on the trim you are considering.

Is now a good time to buy a used 2021 GMC Sierra 1500?

This looks like a moderate, selective buyer’s market, so you can shop with some leverage if you are patient.

• Deal availability: 34.2% of listings are priced as good or great deals.
• Inventory: There are 602 listings available.
• Price trend: Prices have softened 14.00% compared with last year.

If you find a listing below $38,554 CAD, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2021 GMC Sierra 1500's resale value?

The current average of $38,554 CAD sits slightly below last year's $44,832 CAD.

That decline suggests the market has become more favourable for buyers, but it also means future sellers may need to price carefully to stay competitive. If you buy now, you are entering at a lower average price than owners saw a year ago, which can help reduce depreciation pressure in the near term.

The Sierra’s premium positioning and strong owner satisfaction can help support demand, especially for well-equipped examples. Still, resale value will depend heavily on trim, equipment, and how well the truck is presented when you decide to sell.

Vehicles with strong owner satisfaction ratings, like this model year's 4.9/5, tend to retain buyer demand, which supports resale value over time.

Is the 2021 GMC Sierra 1500 safe?

The 2021 GMC Sierra 1500 earns four-star ratings in frontal crash and rollover, and five-star ratings in all other NHTSA tests. The Insurance Institute for Highway Safety rates its front-passenger small-overlap frontal protection as Marginal and its headlights as Poor.

It earns a 4/10 safety score from our experts.

GMC offers forward collision warning, front pedestrian braking, and automatic emergency braking as options, while blind-spot warning and rear cross-traffic warning are included on Denali and optional on other trims. Lane-departure warning, lane-keeping assistance, and a Safety Alert Seat are also available depending on trim.

The main caveat is that the Sierra’s crash-test results are weaker than you would want from a premium-branded truck, so safety should be a careful part of your used-buying decision.

Should I buy a 2021 GMC Sierra 1500 or consider a different year?

If you're weighing the 2021 against nearby model years, here's how to think about it:

Choose the 2021 if:

• 34.2% of listings are priced as good or great deals.
• Price trend: Prices have softened 14.00% compared with last year.
• Owners rate it 4.9/5 — a strong satisfaction signal.
• It offers strong engine performance, upscale styling, and a more refined take on the Sierra formula.

Consider the 2022 if:

• At $45,870 CAD, the 2022 costs more than the current year's $38,554 CAD average.
• It brings a significant makeover with bolder styling, a more lavish interior, and standard high-end technology.

The bottom line: If you want the better value, the 2021 is the smarter buy because prices have softened and inventory is decent. If you want the newer design and are willing to pay more, the 2022 is the upgrade path to consider.

How does the 2021 GMC Sierra 1500 compare to the 2021 Ford F-150?

Our experts score the 2021 GMC Sierra 1500 5.7/10 and the 2021 Ford F-150 7.8/10. The Ford comes out ahead overall, especially if you want a stronger expert-rated package and better fuel economy in the comparison data. The Sierra counters with a higher average used price and a slightly stronger share of good and great deals, but it is the less compelling all-round choice here.

Read our full side-by-side expert comparison here.

These recommendations are based on CarGurus' proprietary market data from November 4, 2026, CarGurus experts' opinions, and generative AI.