In 12-inch skillet, mix chicken, taco seasoning mix and and amount of water called for on seasoning mix packet. Heat to boiling. Reduce heat to medium; simmer uncovered 5 to 10 minutes, stirring occasionally, until water is evaporated. Stir in corn; cook until thoroughly heated.
Heat taco shells or tortillas as directed on package. Fill each shell with 1/4 cup chicken filling. Top each with lettuce, tomato, olives and cheese. Serve immediately.