Zephyrhills is a city in Pasco County, Florida, United States. The population was estimated at 14,381 in the 2014 census. It is a suburb of the Tampa Bay Metropolitan Statistical Area. Zephyrhills is also known as the headquarters of the Zephyrhills bottled water company and is a member of Tree City USA.The community was founded in 1910 by Captain Howard B. Jeffries. Jeffries planned on making the community a home for Civil War veterans. A Founders Day celebration is held annually in March.