Born in Glasgow, Scotland in 1968, this talented young boy, inspired by Star Wars to try acting, got his first taste of it in his schools production of Oliver Twist when he was 10. Boyd's parents were extremely supportive, driving over two hours to get him to the performances, but saddly they past away when he was 12. He was thereafter raised by his grandmother. He realized that he enjoyed acting very much and told his school councelor that was what he wanted to be, but the councelor discouraged this choice and told him to "keep it secret".

When he was 17 he left school and went to work in a book-binding workshop. He worked there 4 years as an apprentice and 2 years as a workman. Strangely, over the years he worked in at the book-binders, the Lord of the Rings trilogy was printed and bound there, many copies bound by his hands. After the 6 years as a book-binder, he was thorougly sick of it. Billy planned on going to America for a year, but before he went he called the Royal Scottish Academy of Music and Drama and asked about applying for when he got back. But it so happened that they still had space for this year and they asked him if he wanted to apply and he did.

Billy was at the drama school in a 3 year course for his bachelors of the arts degree, meanwhile studying everything from Shakespeare to puppet-making. During this time Billy had a few small roles in TV series such as "Down Amongst The Boys" and "Taggart". After graduating he performed in many plays like 'The Slab Boys', 'The Diary of Adrian Mole', etc. at The St. Andrews theatre which were his first paying roles. He then received a call from his agent about the Lord of the Rings movies and if he would like to audition for them. He went along not expecting much, but within a few months Peter Jackson came out to Scotland to meet him and audition him personally. While rehearsing for a show he received a call from his agent who said that the part of Pippin had been offered to him if he wanted it.