Salmon is generally considered to be a healthier choice than tilapia. While both fish are a good source of protein and omega-3 fatty acids, salmon contains more omega-3s and is also a good source of vitamin D and vitamin B12. Tilapia, on the other hand, contains less fat and is a good source of selenium. Ultimately, both fish can be part of a healthy diet, but salmon may be the better choice if you are looking to maximise your omega-3 intake.