He was voiced by John Stephenson in the 1977 film adaptation. In Sir Peter Jackson's live-action films, The Hobbit Trilogy, he is played by Luke Evans, who also portrayed Aramis in the 2011 film, The Three Muskeeters.
Bard is the Lake-man responsible for slaying Smaug after discovering his one weak spot. He is depicted as a champion of the people against the aristocratic and egoistical Master of Lake Town.
He rallied the guards to defend the town when the Dragon came. Bard was able to slay the dragon Smaug with the Black Arrow after a tip from the old thrush (who had overheard Bilbo’s description of Smaug.
Rankin and Bass' The Hobbit
Bard appears in the 1977 Rankin and Bass film adaptation of The Hobbit. He appears to be in charge of the city, Lake-town, as there is no Master of Lake-town present.
He later forges alliances with Thranduil to take their share of the treasure by force. Later, they forge an alliance with Thorin Oakenshield in defeating the Orcs.
Peter Jackson's The Hobbit trilogy
Bard also appears in The Hobbit trilogy by Peter Jackson, although various changes were made.
The Hobbit: The Desolation of Smaug
Bard meets Thorin and Company muchearlier than in the novel. In this film, he smuggles the company into Lake-town. Also, in addition to having a son, Bard is given two daughters: Sigrid and Tilda.
Upon discovering that one of the dwarves he smuggled was Thorin, the king under the mountain, Bard remembers the prophecy that foreshadows the destruction of Lake-town. He is the only one who voices his concern about the dwarf company reclaiming the mountain, as it will awaken Smaug. However, Bard is ridiculed by the other townsfolk. The morning Thorin and Company leave, Bofur, Fíli, and Óin come to Bard's house. The man initially rejects them until he learns that one of the dwarves, Kíli, is sick and allows them to take refuge at his house for Kíli to be healed.
Though he tries providing them with various medicines, Bard does not have the kingsfoil Óin needs. While attending to Kíli, they hear Smaug awaken in the mountain and decides to use the black Arrow when it comes. However, Bard separates from Bain (who came with his father) and has him hide the Black Arrow. Bard is knocked unconscious and wakes up in a cell. He warns the guards that they have no idea what is coming as the movie comes to a close.
The Hobbit: The Battle of the Five Armies