- Source of Wealth: Business (Finance)
- Age: 61
- Birth Place: United Kingdom
- Full Name: Mary Theresa Barry
- Nationality: British
- Date of Birth: September 1958
- Ethnicity: English
- Occupation: Businesswoman
- Education: Bristol University
A politics graduate from Bristol University, Mary Theresa Barry became the group marketing director at Hargreaves Lansdown, the investment and fund platform business co-founded by Peter Hargreaves (qv) and Steve Lansdown (qv). She previously worked in London for Abbey Unit Trust Managers. Barry has a stake worth $172.17 million in Hargreaves Lansdown.
Mary Theresa Barry eventually became the biggest shareholder of Hargreaves London. She was able to join Hargreaves London as the company’s first full-time employee in the year 1982.