Lena Roos is a historian of religion. Among her research interests are:
- Judaism
- Interreligious coexistence, especially during the Middle Ages
- Teaching religion, especially through role play and excursions
- The historiography of History of Religions
- Religion and popular culture
- Religion and food
- Religion and sexuality
- Religion and gardening
In the past she has taught at Uppsala University (Faculties of Theology and Languages), Stockholm School of Theology, University College of Gävle, and Lund University. Before her doctoral training she worked as a journalist.
At present she is involved in three research projects:
1. God of Small Things: Jewish Early Modern pious literature for women
2. Jewish identities around the Baltic Sea
3. Gardening for God and neighbor: faith-based community gardens in urban settings