Used 2021 GMC Sierra 3500HD for Sale near Ontario

## Summary - With 94 currently listed for sale and an **average price of $68,158.00 CAD**, 27.7% of 2021 GMC Sierra 3500HDs for sale on CarGurus are rated as good or great deals. - **Favourably reviewed:** Owners rated the 2021 GMC Sierra 3500HD 5 / 5 stars. - **100.0% of 2021 Sierra 3500HD models on CarGurus are accident free**. ## Why it stands out The 2021 GMC Sierra 3500HD is notable for its impressive hauling and towing capabilities, making it an excellent choice for those needing a robust work truck with the comforts of a higher-end vehicle. It carries over the fifth-generation updates that improve its power, comfort, and technological features compared to its predecessors. Particularly, the Sierra 3500HD can tow up to 16,100 kilograms (35,500 pounds) when equipped correctly, allowing it to surpass many competitors in the heavy-duty truck class. Additionally, it offers a variety of trim levels to cater to different needs, from the no-frills work-minded base model to the luxurious Denali trim with upscale features. Despite its strong capabilities, some users may find the larger models unwieldy in tight spaces, and the top trims come with a significant price tag which may not appeal to all buyers. ## Other model years to consider - **[2024 GMC Sierra 3500HD](https://www.cargurus.ca/Cars/l-Used-2024-GMC-Sierra-3500HD-c32775)** - Average price: $82,734.00 CAD - Good/great deal percentage: 30.7% - User rating: 5 / 5 - Total listings: 150 - **[2025 GMC Sierra 3500HD](https://www.cargurus.ca/Cars/l-Used-2025-GMC-Sierra-3500HD-c33463)** - Average price: $95,078.00 CAD - Good/great deal percentage: 32.8% - User rating: 5 / 5 - Total listings: 119 - **[2023 GMC Sierra 3500HD](https://www.cargurus.ca/Cars/l-Used-2023-GMC-Sierra-3500HD-c32422)** - Average price: $76,604.00 CAD - Good/great deal percentage: 28.8% - User rating: Not available - Total listings: 146 This analysis is based on CarGurus' proprietary market data from May 18, 2026, CarGurus experts' opinions, and generative AI.