Leslie Grace was born on January 7, 1995 in The Bronx, a borough of New York City. She was raised and attended school in Davie, Florida. Grace, born to Dominican parents, was entertaining her five older siblings and parents when she could barely speak, at the age of two.

She speaks fluent English and Spanish. Her family gave her the confidence to trust in her talent and pursue success doing what she loves: writing and performing songs. She launched her professional career with her single, "Will U Still Love Me Tomorrow", a bilingual, bachata cover of the 1961 Shirelles hit, co-written by Carole King.

Her version peaked at number one on both the Billboard Tropical Songs chart and Billboard Latin Airplay charts, becoming the youngest female artist to do so.