Billie Eilish. Billie Eilish was 20 in When Billie Met Lisa as 'Billie Eilish (voice)'.FINNEAS. FINNEAS was 24 in When Billie Met Lisa as 'Finneas O'Connell (voice)'.Yeardley Smith. Yeardley Smith was 57 in When Billie Met Lisa as 'Lisa Simpson (voice)'.Nancy Cartwright. Nancy Cartwright was 64 in When Billie Met Lisa as 'Bart Simpson (voice)'.Chris Edgerly. Chris Edgerly was 52 in When Billie Met Lisa as 'Additional Voices (voice)'.Sunkrish Bala. Sunkrish Bala was 37 in When Billie Met Lisa as 'Additional Voices (voice)'.David Silverman. David Silverman was 65 in When Billie Met Lisa as 'Director'David Mirkin. David Mirkin was 66 in When Billie Met Lisa as 'Writer, Producer'Cesar Mazariegos. Cesar Mazariegos was >> in When Billie Met Lisa as 'Writer'Elisabeth Kiernan Averick. Elisabeth Kiernan Averick was >> in When Billie Met Lisa as 'Writer'James L. Brooks. James L. Brooks was 81 in When Billie Met Lisa as 'Producer'Richard Raynis. Richard Raynis was >> in When Billie Met Lisa as 'Producer'Dominique Braud. Dominique Braud was >> in When Billie Met Lisa as 'Associate Producer'Roger Injarusorn. Roger Injarusorn was >> in When Billie Met Lisa as 'Editor'Travis Powers. Travis Powers was >> in When Billie Met Lisa as 'Sound Effects Editor'Chris Ledesma. Chris Ledesma was 64 in When Billie Met Lisa as 'Music Editor'Bleeding Fingers Music. Bleeding Fingers Music was >> in When Billie Met Lisa as 'Music'Dima Malanitchev. Dima Malanitchev was >> in When Billie Met Lisa as 'Art Direction'Danielle Weisberg. Danielle Weisberg was >> in When Billie Met Lisa as 'Script Coordinator'Alexa Patterson. Alexa Patterson was >> in When Billie Met Lisa as 'Script Coordinator'Juliet Kaufman. Juliet Kaufman was >> in When Billie Met Lisa as 'Script Coordinator'