Leticia Castillo was born in Riverside, California, and completed her vocational education in cosmetology before enrolling in college. She earned a Bachelor of Science in Human Services and later a Master of Arts in Counseling Psychology with specializations in Marriage and Family Therapy and Professional Clinical Counseling. Castillo spent nearly 15 years in the telecommunications sector before transitioning to a career in mental health services. She has experience in both public and private sectors, including roles in community mental health and private practice as a licensed clinical psychotherapist.

Leticia Castillo's political identity is marked by a distinctive blend of conservative social values and fiscally restrained policies. Her advocacy for parental rights, including opposition to gender-affirming healthcare and pronoun usage in schools, juxtaposes with a generally low-tax approach, hinting at an ideologically agile strategy. Castillo's emphasis on public safety and the protection of the unborn aligns with traditional conservative values, yet her nuanced stance on lowering the cost of living suggests an awareness of economic pressures faced by Californians. This tension between fiscal conservatism and protective social policies makes her a compelling figure in contemporary political discourse.