Taiwan has been controlled by various governments and has been associated with various flags throughout its history. Since 1945, the Republic of China controls the island; thus the flag most commonly associated with it is the Flag of the Republic of China
Below are the flags used in the political divisions of Taiwan.
高雄市
http://www.kcg.gov.tw/CP.aspx?n=1FA00AF1B01EEB41&s=B5FC50A1C806D74A
新北市
http://www.ntpc.gov.tw/ch/home.jsp?id=53&parentpath=0,5,10