Yes, but get the right kind.

The 2019 Mac Pro is an Intel Xeon W workstation. Apple only shipped it with Xeon W chips, and ECC memory is mandatory — the machine won’t boot without it. So you’re not choosing between ECC and non‑ECC; you’re choosing the right ECC sticks.

The catch: the Mac Pro uses RDIMMs (registered ECC) or LRDIMMs, not the cheaper unbuffered ECC DIMMs you might find in a consumer board. Also, Apple’s firmware can be picky about third‑party RAM — I’ve heard stories of perfectly good Micron server sticks getting rejected. Stick to OWC, Crucial, or other vendors that explicitly list Mac Pro 2019 compatibility.

Oh, and don’t mix capacities or speeds across channels unless you like running at the slowest common denominator. That applies to any workstation, not just Apple.