Used 2021 Mercedes-Benz GLS for SaleNationwide

How much does the 2021 Mercedes-Benz GLS cost?

Prices have softened 9.98% compared to this time last year, making it a favourable time to shop this model year.

There are 58 listings available, which suggests a healthy amount of inventory for you to compare.

Is the 2021 Mercedes-Benz GLS a good car?

Yes — 4.7/5 is a strong user rating for this model year, and the expert score is 8.3/10. The model scores 9/10 across Look and feel, Performance, Technology, and Safety.

The 2021 Mercedes-Benz GLS is positioned as the S-Class of SUVs, so you should expect a higher standard of luxury than many full-size, three-row rivals. It also brings surprising performance, which broadens its appeal beyond pure comfort. Inside, it prioritizes space and comfort, with three rows of seating and enough room for people and cargo.

There are 24.1% good or great deals in the market, which gives you some room to shop selectively.

Is the 2021 Mercedes-Benz GLS reliable?

Owners rate it 4.7/5, a strong signal of long-term satisfaction.

The GLS is described as a highly comfortable, well-finished luxury SUV, and the expert assessment highlights its holistic approach to luxury. Its performance content also points to strong engineering, with the EQ Boost mild-hybrid system helping add torque when needed and supporting smoother operation. The result is a vehicle that feels engineered for refinement as much as speed.

If you buy used, your main long-term ownership risk is paying a premium for a complex luxury SUV, so condition and maintenance history matter a lot.

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

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 premium sound system. The GLS 580 adds V8 power and more content, while the AMG GLS 63 brings more aggressive bodywork, a quad-outlet exhaust, and a performance-inspired cabin.
• Powertrain: The GLS 450 uses a twin-turbocharged 3.0-litre inline-six with 362 horsepower and 369 pound-feet of torque. The GLS 580 uses a twin-turbocharged 4.0-litre V8 with 483 hp and 516 lb-ft, and the AMG GLS 63 uses a hand-crafted 4.0-litre twin-turbo V8 with 603 hp and 627 lb-ft. All engines include Mercedes’ EQ Boost 48-volt mild-hybrid system.
• Safety package: Standard equipment includes Active Brake Assist, rain-sensing wipers, automatic high beams, automatic parking assist, a driver-drowsiness monitor, crosswind assist, front-and-side-impact airbags, traction control, self-tensioning seatbelts, and a tire-pressure monitoring system. Available safety tech includes lane-change assist, adaptive cruise control, blind spot monitoring, rear cross-traffic alert, a following-distance indicator, and stop-and-go cruise control.
• Infotainment: The GLS comes standard with the MBUX infotainment system, a massive touch screen, a central trackpad controller, Apple CarPlay, Android Auto, and voice control through “Mercedes” or “Hey Mercedes.” The digital dash and touch-sensitive steering-wheel controls add capability, but there is a learning curve.
• Fuel efficiency: The most-efficient variant uses 12.0 litres per 100 kilometres in city driving, 9.8 on the highway, and 11.0 combined. In week-long mixed driving, the observed average was 15.4 L/100 km.

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 best-value starting point if you want the GLS experience with the core luxury and tech features already included. You get the standard MBUX system, heated front seats, wireless charging, Apple CarPlay, Android Auto, and the Burmester audio system.
• GLS 580: Choose this if you want more power and a richer feature set without jumping all the way to the AMG model. It adds V8 performance and opens the door to the Premium Rear Seating Package with heated, ventilated, and massaging second-row seats, plus extra air bags and five-zone climate control.
• Mercedes-AMG GLS 63: This is the one for you if performance matters most. It adds the most aggressive styling, the strongest engine, and a more driver-focused character, but it is the most expensive route.

The GLS also offers several safety and convenience features, with additional driver-assistance tech available beyond the standard equipment.

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

This looks like a moderate, selective buyer’s market, so you can shop carefully and still find worthwhile listings.

• Deal availability: 24.1% of listings are priced as good or great deals.
• Inventory: There are 58 listings available.
• Price trend: Prices have softened 9.98% compared with last year.

If you find a listing below $65,599 CAD, 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 $68,492 CAD sits slightly below last year's $76,082 CAD.

That price decline suggests the market has become more favourable for buyers, but it also means future sellers may need to be realistic about pricing. If you buy at today’s average, you may have less room for appreciation than in a stronger market. On the other hand, the GLS’s luxury positioning and strong demand for three-row premium SUVs can help support values if the vehicle is well kept.

Vehicles with strong owner satisfaction ratings, like this model year's 4.7/5, tend to retain buyer demand, which supports resale value over time.

Is the 2021 Mercedes-Benz GLS safe?

It earns a 9/10 safety score from our experts.

The GLS comes standard with Active Brake Assist, rain-sensing wipers, automatic high beams, automatic parking assist, a driver-drowsiness monitor, crosswind assist, and a full array of front-and-side-impact airbags. Available safety tech includes lane-change assist, adaptive cruise control, blind spot monitoring, rear cross-traffic alert, a following-distance indicator, and stop-and-go cruise control.

That gives you a strong standard safety foundation, with extra driver-assistance features available if you want more convenience and confidence.

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:

• 24.1% of listings are priced as good or great deals.
• Price trend: Prices have softened 9.98% compared with last year.
• Owners rate it 4.7/5 — a strong satisfaction signal.
• The 2021 GLS delivers S-Class-like luxury with three rows of space and surprising performance.

Consider the 2022 if:

• At $68,541 CAD, the 2022 costs more than the current year's $68,492 CAD average.
• It adds a broader Canadian model range, including the Mercedes-Maybach GLS 600 4Matic.

The bottom line: If you want the best mix of value and luxury, the 2021 is the smarter buy. If you are willing to pay a bit more for the newer model-year context and broader trim availability, the 2022 is worth a look. Price-sensitive buyers should focus on the 2021, especially if they find a well-priced listing near the low end of the range.

How does the 2021 Mercedes-Benz GLS compare to the 2021 BMW X7?

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.