He played Peregrin "Pippin" Took in Peter Jackson's epic film trilogy The Lord of the Rings (2001–2003), Barret Bonden in Master and Commander: The Far Side of the World (2003) and Glen and Glenda (later G.G.

After graduating from the Royal Scottish Academy of Music and Drama, he went on to perform with St Andrews Repertory and the Traverse Theatre.

Boyd wrote the melody for and sang the song "The Edge of Night", which was featured in The Lord of the Rings: The Return of the King.

He performed at the Dundee Repertory Theatre in the role of Davie in Sunshine on Leith, as well as in Long Hong Jimmy, in which he was the lead actor.

He also starred (2007) as Richard MacDuff in the BBC Radio adaptation of the book: Dirk Gently′s Holistic Detective Agency written by Douglas Adams.

Boyd together with fellow The Lord of the Rings castmates Sean Astin, Sean Bean, Orlando Bloom, Ian McKellen, Dominic Monaghan, Viggo Mortensen, Miranda Otto, John Rhys-Davies, Andy Serkis, Liv Tyler, Karl Urban, and Elijah Wood, plus writer Philippa Boyens and director Peter Jackson on 31 May 2020 joined Josh Gad's YouTube series Reunited Apart which reunites the cast of popular movies through video-conferencing, and promotes donations to non-profit charities.

He made his stage debut in 2024 with The Lord of the Rings castmate Dominic Monaghan in the Canadian production of Tom Stoppard's Rosencrantz and Guildenstern Are Dead.

[8][9] The band was named after a time when Boyd's Lord of the Rings co-star Dominic Monaghan sent a picture of a cake covered in bees.

[10] Boyd made a guest appearance on Viggo Mortensen's 2003 album Pandemoniumfromamerica, where he played the bass on two songs, as well as drums on another.

In 2014, Boyd wrote and performed the song "The Last Goodbye", which was played over the ending credits of the movie The Hobbit: The Battle of the Five Armies.

Monaghan revealed in an interview for the national breakfast television show GMTV that he continues to see Boyd on a regular basis, as he is "essentially, kind of, godfather to his kid."