Used 2021 Mercedes-Benz GLS for Sale nearMesa, AZ

How much does the 2021 Mercedes-Benz GLS cost?

Prices have softened 8.61% compared to this time last year, making it a favorable time to shop this model year.

There are 870 listings available, which gives you a meaningful amount of inventory to compare.

Is the 2021 Mercedes-Benz GLS a good car?

Yes — 4.67/5. The expert rating is 8.33/10, and the model scores 9/10 across Look and feel, Performance, Technology, and Safety.

The 2021 Mercedes-Benz GLS is positioned as a full-size luxury SUV that aims to bring S-Class-style refinement to a three-row format. It stands out for spacious seating and cargo flexibility, with room for groceries, weekend bags, and larger items that would be difficult to manage in a sedan.

The trade-offs are clear: the third row is cramped, the technology can be unintuitive, and fuel economy is poor. Even so, if you want a premium three-row SUV with strong performance and a high-end cabin, this one fits that brief well.

Only 39.8% of listings are priced as good or great deals, so the best examples may move quickly.

Is the 2021 Mercedes-Benz GLS reliable?

Owners rate it 4.67/5, a strong signal of long-term satisfaction.

The GLS is described as a comfortable, well-finished luxury SUV with a composed ride and strong overall capability. Its powertrains are paired with Mercedes’ EQ Boost mild-hybrid system, which adds extra output when needed and helps the turbochargers spool more quickly.

The GLS also benefits from a broad standard equipment list, including features that support everyday usability and convenience. That said, the technology can take time to learn, so used buyers should make sure the controls feel intuitive before committing.

If you plan to keep it long term, the biggest ownership risk is that a complex luxury SUV can be expensive to live with if maintenance or repairs stack up.

What should I look for when buying a used 2021 Mercedes-Benz GLS?

Accident-free inventory is solid at 84.6% — always verify the vehicle history report.

You should still check the history report carefully, because a clean listing percentage does not replace a proper records review. Prioritize a pre-purchase inspection that focuses on electronics, suspension behavior, and interior condition, since this is a feature-rich luxury SUV. Pay close attention to how the third row, infotainment controls, and driver-assistance systems operate in real use.

Key things to evaluate:

• Trim level: The GLS 450 includes remote keyless entry, remote start, nine USB ports, dual-zone automatic climate control, heated front seats, a power liftgate, wireless device charging, Apple CarPlay, Android Auto, satellite radio, and a 13-speaker Burmester sound system. The GLS 580 adds heated-and-cooled front seats, massaging front seats, illuminated running boards, soft-close doors, and five-zone automatic climate control. The Mercedes-AMG GLS 63 adds more aggressive bodywork, a quad-outlet exhaust, and a performance-inspired cabin. The GLS 450 is the best-value trim if you want the core luxury and tech without stepping too far up the price ladder.
• Powertrain: The GLS 450 uses a twin-turbocharged 3.0-liter inline-six with 362 horsepower and 369 pound-feet of torque. The GLS 580 uses a twin-turbocharged 4.0-liter V8 with 483 hp and 516 lb-ft. The AMG GLS 63 uses a hand-crafted 4.0-liter twin-turbo V8 with 603 hp and 627 lb-ft. All engines include EQ Boost 48-volt mild-hybrid assistance.
• Safety package: Standard equipment includes Active Brake Assist, forward-collision avoidance, rain-sensing wipers, blind-spot monitoring, automatic high beams, automatic parking assist, a surround-view camera system, a driver-drowsiness monitor, and crosswind assist. Available features include lane-keep assist, lane-change assist, adaptive cruise control, a following-distance indicator, and stop-and-go cruise control.
• Infotainment: The GLS uses the MBUX system with a massive touch screen, a trackpad controller, Apple CarPlay, Android Auto, and voice control through “Mercedes” or “Hey Mercedes.” The system is designed around large, easy-to-read icons, but it can still take time to learn.
• Fuel efficiency: The GLS 450 returns 20 mpg city, 24 highway, and 21 combined. The GLS 63 returns 14 mpg city, 18 highway, and 16 combined. In mixed driving, the GLS 63 averaged 15.3 mpg.

Which 2021 Mercedes-Benz GLS trim should I buy?

The 2021 Mercedes-Benz GLS is offered in 3 trim levels: GLS 450, GLS 580, and Mercedes-AMG GLS 63.

Here's the short version:

• GLS 450: This is the trim to start with if you want the GLS experience at the lowest entry point. It already brings a long list of luxury and tech features, including heated front seats, wireless charging, Apple CarPlay, Android Auto, and the Burmester audio system.
• GLS 580: This trim adds V8 power and a more upscale feature set, including massaging front seats, soft-close doors, and five-zone climate control. It makes sense if you want more performance and comfort without going all the way to AMG territory.
• Mercedes-AMG GLS 63: This is the performance-focused choice, with the most powerful engine, more aggressive styling, and a sportier cabin. It suits you best if outright speed and character matter more than value.

The GLS also offers optional safety and driver-assistance features such as lane-keep assist, lane-change assist, adaptive cruise control, and stop-and-go cruise control.

Is now a good time to buy a used 2021 Mercedes-Benz GLS?

This is a moderate market for selective buyers, with enough softness in pricing to reward comparison shopping.

• Deal availability: 39.8% of listings are priced as good or great deals.
• Inventory: There are 870 listings available.
• Price trend: Prices have softened 8.61% compared with last year.
• Clean inventory: 84.6% of listings are accident-free.

If you find a listing below $46,071, that's toward the low end of the year-round range and worth acting on quickly.

What is the 2021 Mercedes-Benz GLS's resale value?

The current average of $46,614 sits slightly below last year's $51,008.

That decline suggests the market has already adjusted downward, which can help you buy more confidently today. For a future seller, it also means your resale outcome will depend heavily on condition, mileage, and equipment rather than broad market appreciation.

Because the GLS sits in the luxury SUV segment, well-kept examples with desirable features should remain easier to market than neglected ones. Strong presentation and a clean history will matter a lot when it is time to sell.

Vehicles with strong owner satisfaction ratings, like this model year's 4.67/5, tend to retain buyer demand, which supports resale value over time.

Is the 2021 Mercedes-Benz GLS safe?

The GLS earns a 9/10 safety score from our experts.

Standard driver-assistance equipment includes Active Brake Assist, forward-collision avoidance, blind-spot monitoring, automatic high beams, automatic parking assist, a surround-view camera system, a driver-drowsiness monitor, and crosswind assist. Available upgrades include lane-keep assist, lane-change assist, adaptive cruise control, a following-distance indicator, and stop-and-go cruise control.

That gives you a strong safety foundation even before optional features are added. If you are shopping used, make sure the specific vehicle you are considering has the driver-assistance features you want, since some are optional rather than standard.

Should I buy a 2021 Mercedes-Benz GLS 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:

• 39.8% of listings are priced as good or great deals.
• Accident-free inventory is solid at 84.6% — always verify the vehicle history report.
• Price trend: Prices have softened 8.61% compared with last year.
• Owners rate it 4.67/5 — a strong satisfaction signal.
• The 2021 GLS delivers S-Class-style refinement in a spacious three-row SUV.

Consider the 2022 if:

• At $46,133, the 2022 costs less than the current year's $46,614 average.
• Mercedes simplified the lineup around the base six-cylinder GLS 450.

The bottom line: If you want the broader 2021 lineup with multiple powertrain choices and a strong value backdrop, this year is the better target. If you are price-sensitive and only need the base six-cylinder model, the 2022 is worth a look.

These recommendations are based on CarGurus' proprietary market data from October 20, 2026, CarGurus experts' opinions, and generative AI.