Heat oil in a skillet over medium heat. Cook and stir onion and garlic in hot oil until soft and translucent, 5 to 10 minutes.
Heat a large pot over medium-high heat. Cook and stir turkey and chili seasoning in hot pot until turkey is browned and crumbly, 5 to 10 minutes.
Stir onion-garlic mixture into turkey mixture.
Add chili beans, corn, black beans, water, diced tomatoes, and tomato paste; stir. Bring to a simmer, reduce heat to low, and simmer until flavors blend, 1 hour.