Remove any loose or damaged outer husk layers and trim the threads sticking out at the top, but keep the majority of each husk intact to protect the kernels while grilling.
Gently pull back the husks on each ear without removing them completely. Remove as much silk as possible, then fold the husks back over the corn to cover it completely.
Soak the ears of corn with the husks on in a large bowl or sink of cool water for 20–30 minutes. This helps prevent the husks from burning and keeps the corn moist.
Preheat the grill to medium-high heat (about 375–450°F).
Place the soaked corn directly on the grill grates. Grill for 20–25 minutes, turning every 5 minutes so the husks char evenly and the kernels cook through.
Check for doneness by carefully peeling back the husk from one ear. Use caution—steam will escape. The kernels should be bright yellow and fork-tender.
Remove the corn from the grill and let it cool slightly. Peel back the husks and remove any remaining silk.