It's Always Sunny in Philadelphia Season 16 full movie online on FMovies. In Season sixteen, it’s a challenge for Ronald “Mac” MacDonald, Charlie Kelly, Dennis Reynolds, Dee Reynolds, and Frank Reynolds who yearn for the past as they attempt to survive in 2023. This year alone, Mac battles with allergies and long-distance dating, Charlie takes on his long-forgotten sisters, Dee fights for rent control and women’s athletics, Frank wrestles for his gun, and Dennis struggles to improve his mental health. At the end of the day, they’re navigating 2023 with 16 years of baggage as a few figures from their past rear their heads.