Selim Bradley is the son of Führer King Bradley.

In the manga and 2009 anime series, Selim is the Führer's sprightly son. He frequently asks his father to tell him stories from the battlefront and interesting anecdotes from his everyday events. Selim professes a desire to become a State Alchemist so as to be more useful to the Führer and is a self-professed fan of Edward Elric.

(Source: FMA Wikia)