Leah Tillman Sullivan has called the North Fork home for nearly all her life. In 1973, her father Art — who would go on to serve as longtime chair of the Southold Town Democratic Committee — moved the family to Mattituck, and it's where she grew up. After graduating from Mattituck High School, she headed to Lafayette College in Easton, Pennsylvania, where she earned a Liberal Arts degree. Her time in college included a year abroad in Vienna studying German.

Leah's professional career bridges government service and local business. She spent twelve years as a Senior Congressional Aide to Congressman Tim Bishop, where she played a key role in supporting his legislative agenda and worked on constituent relations, community outreach, and communications. Her portfolio included complex casework on immigration, visas, and Social Security — work that demanded quick critical thinking, clear communication, and close attention to detail.

Closer to home, she served as Executive Director of the North Fork Chamber of Commerce, overseeing its financial health and all administrative and management functions. After years supporting local businesses, she then became part of one: the Village Cheese Shop on Love Lane in Mattituck, where she spent eight years as Marketing Director juggling a range of responsibilities — customer relations, special events, catering, and daily operations. She holds a real estate license as well, with hands-on experience calculating the market value of Southold Town properties — background she applies directly in her work at the Assessor's Office.

As Tax Assessor, Leah is committed to an office where assessments are fair, decisions are transparent, and residents can get straight answers about their property and any exemptions they qualify for. The Assessor's Office administers dozens of exemption programs — from STAR and senior citizen exemptions to veterans' and agricultural exemptions — and Leah sees ensuring that residents know what they're entitled to as a core part of the job.