Heat grill to high; lightly oil grates. In a medium bowl, combine cherries, onion, cilantro, jalapeno, and lime juice. Season with salt and pepper, and toss to combine; set salsa aside.
In a small bowl, stir together coriander, 1 teaspoon salt, and 1/4 teaspoon pepper. Rub tilapia all over with oil; sprinkle with spice mixture.
Grill tilapia until opaque around the edges and underside loosens easily from grill, 2 to 3 minutes. Using a metal spatula with a thin blade, flip fish; continue to cook until opaque throughout, 2 to 3 minutes. Serve tilapia topped with cherry salsa.