Place chicken breasts into the slow cooker.
Sprinkle taco seasoning over the chicken.
Pour salsa and chicken broth over the seasoned chicken.
Cover and cook on low for 4 hours until chicken is tender and cooked through.
Shred the chicken with two forks and mix well with the sauce in the slow cooker.
Warm taco shells according to package instructions.
Fill each taco shell with shredded chicken, then top with lettuce, cheese, tomatoes, and sour cream.
Serve and enjoy your Slow-Cooker Chicken Tacos.