Flainn is a surname. Notable people with the surname include: Aenghus Ua Flainn Ailill Corrach mac Flainn (died 741), king of the Uí Failge, a Laigin people of County Offaly Cináed mac Flainn (died 770), king of the Uí Failge, a Laigin people of County Offaly Conaing mac Flainn (died 849), King of Brega from the Uí Chonaing sept of Cnogba (Knowth) of the Síl nÁedo Sláine branch of the southern Ui Neill Cummascach mac Flainn (died 757), king of the Uí Failge, a Laigin people of County Offaly Donnchad Donn mac Flainn Fithceallach mac Flainn Flaithnia mac Flainn (died 755), king of the Uí Failge, a Laigin people of County Offaly Flann Mac Flainn Mugrón mac Flainn (died 782), king of the Uí Failge, a Laigin people of County Offaly Nicol Mac Flainn Ragnall Ua Flainn Chua Tóim Snáma mac Flainn (died 770), King of Osraige in modern County Kilkenny Ólchobar mac Flainn (died 796), supposed King of Munster from the Uí Fidgenti of County Limerick
See also Emily Flain, a Northern Irish actress Flain, a character from animated TV series Mixels Flaine, a ski area in the French Alps