Beau Sia was born in Ohio. He is of Chinese Filipino descent. Raised in Oklahoma City, Oklahoma, Sia discovered spoken word poetry on MTV as a teenager. When not participating in his high school's swim team, he spent time at Oklahoma City's only open mike night.
In 1995, Sia moved to New York City, where he attended the New York University's Tisch School of the Arts dramatic writing program. He has said that moving to New York made him conscious of his identity as an Asian American, something that he denied often in Oklahoma City. His cultural identity became a common theme in his poems.
Sia began performing at the Nuyorican Poets Cafe, eventually earning himself a place on the 1996 Nuyorican National Poetry Slam team. That same year, he would be filmed for the documentary SlamNation. The film followed Sia and his Nuyorican teammates (Saul Williams, Jessica Care Moore and muMs da Schemer) as they competed at the 1996 National Poetry Slam. The team would go on to place third in the nation, and have a lasting impact on how people would view slam poetry. In the book Words In Your Face: A Guided Tour Through Twenty Years of the New York City Poetry Slam, author Cristin O'Keefe Aptowicz wrote of Sia's impact, noting
“Beau Sia took Maggie Estep's pop culture reference-heavy work to the next level, bouncing across the stage, frenzied and electrified. His work was confrontational, hilarious and unapologetic. Sia was a firebrand who seemed determined to smash the prevailing stereotypes of Asian-America, the ones that painted Asian-Americans as being meek, passive and voiceless.”
Sia's relationship with the Poetry Slam community continued. He eventually earned two National Poetry Slam Championships in 1997 and 2000 while competing on the NYC-Urbana national poetry slam team. He would also reach second place in the Individual Poetry Slam competition in 2001.
He wrote a parody of Jewel's work, A Night Without Armor, within four hours and published it as A Night Without Armor II: the Revenge in 1998. He wrote different poems with Jewel's original titles, lampooning her earnest lines. It is painfully detailed in its satire, changing the delicate paintings printed in Jewel's book to rough, humorous pencil drawings by Sia. The front and back cover were also painstakingly mirrored.
Sia then began touring around Europe and the United States. He also appeared in films and published a wide range of his works in book and compact disc form.