In a medium-sized bowl, add the diced tomatoes, chopped cilantro, finely chopped red onion, minced jalapeño, lime juice, olive oil, and a pinch of salt.
Mix all the ingredients together gently until well combined.
Taste and adjust the seasoning by adding more lime juice or salt, if needed.
Cover and store the Pico de Gallo in an airtight container in the refrigerator for at least 15 minutes to let the flavors meld together.
Serve as a dip with tortilla chips, or use it as a topping for tacos, grilled meats, or scrambled eggs.