Where are the most common places to find omega 3 fats?

Omega 3. The best place to get your nutrients is from regular food, not supplements (there are exceptions for individual people). Omega 3 fats are found in general in ocean fish, walnuts, flaxseed oil, canola oil and spinach.
Omega 3 fats. The most known source of omega 3s is fish oil. You can certainly also get omega 3s from other sources, like chia seeds.
Omega. Fatty fish are good sources. The commonest place is probably in the droves of fish oil pills being sold.