Bring the quinoa and water to a boil in a saucepan over high heat. Once boiling, reduce heat to medium-low and simmer until the quinoa is tender and the liquid has been absorbed, about 15 minutes.
Remove from heat and fluff with a fork. Transfer to a large bowl and let cool completely.
Add the onion, bell pepper, olive oil, garlic, salt and pepper. Stir until combined.