Lia Claxton was born in 2004 to parents Shawn Claxton and Tessa Smith-Claxton and raised in the village of Long Look, on the island of Tortola. She is the third of four children. Her older sisters Lakiesha and Natisha Claxton are identical twins and her younger brother is Mychael. As a child, Claxton was a student of music and dance, and still plays the piano on occasion at her local church.

Claxton fell in love with track and field after joining a track club in the aftermath of hurricanes Irma and Maria. It provided structure and discipline for the local youth during an uncertain and chaotic period of time wherein storms had destroyed most major infrastructure. The sport taught her to be focused and resilient in order to push through failures and disappointment, even when physically and emotionally draining.

Claxton received a Christian education and graduated from high school during the pandemic. She earned an Associates of Arts degree in Humanities from the H Lavity Stoutt Community College. She is pursuing an English degree and aspires to become a lawyer. She currently works as a receptionist and junior secretary at a law firm.