Season salmon fillets with salt and pepper. Place on the grill skin-side down and cook on each side for 3 to 4 minutes or until internal temperature reaches 145 degrees Fahrenheit for medium doneness.
As the salmon cooks, prepare the salsa. In a large bowl, toss together corn, red onion, tomatoes, avocado, olive oil, lime juice, lime zest, salt and pepper until well combined.
Plate salmon and top with a generous portion of salsa. Garnish with cilantro