Used 2021 GMC Sierra 3500HD for Sale near Ontario

## Summary - With 87 currently listed for sale and an **average price of $68,175.00 CAD**, 20.7% of 2021 GMC Sierras 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 continues the legacy of GMC’s heavy-duty trucks with impressive towing and hauling capabilities, coupled with a blend of refinement and luxury not typically found in this truck segment. Known for its robust performance, the Sierra 3500HD is particularly commendable for its maximum towing capacity of up to 16,100 kilograms (35,500 pounds) when equipped with the right configuration, thanks to its durable construction and powerful engine options. This model year also features advanced technology for towing and safety, including a MultiPro tailgate and a suite of driver assistance features, making it an appealing choice for those who need to handle demanding tasks. The optional 6.6-litre Duramax turbodiesel engine elevates the Sierra's performance further, providing both power and efficiency. However, while the higher trim levels can become quite costly, the base model retains the essence of a workhorse, making it suitable for buyers looking for practicality without unnecessary frills. Overall, the 2021 GMC Sierra 3500HD excels by marrying utility with comfort and advanced technology, positioning itself as an appealing choice in the heavy-duty truck market. ## Other model years to consider - **[2024 GMC Sierra 3500HD](https://www.cargurus.ca/Cars/l-Used-2024-GMC-Sierra-3500HD-c32775)** - Average price: $82,176.00 CAD - Good/great deal percentage: 31.5% - User rating: 5 / 5 - Total listings: 146 - **[2025 GMC Sierra 3500HD](https://www.cargurus.ca/Cars/l-Used-2025-GMC-Sierra-3500HD-c33463)** - Average price: $96,842.00 CAD - Good/great deal percentage: 35.3% - User rating: 5 / 5 - Total listings: 116 - **[2023 GMC Sierra 3500HD](https://www.cargurus.ca/Cars/l-Used-2023-GMC-Sierra-3500HD-c32422)** - Average price: $76,033.00 CAD - Good/great deal percentage: 27.1% - Accident-free percentage: 100.0% - Total listings: 140 This analysis is based on CarGurus' proprietary market data from May 11, 2026, CarGurus experts' opinions, and generative AI.