Leo A Daly Established in 1915, Leo A Daly is an internationally renowned architecture, planning, engineering, interior design and program management firm. Our portfolio includes award-winning projects in 77 countries, all 50 states, and the District of Columbia. The firm currently employs approximately 800 architects, planners, engineers and interior designers in 30 offices worldwide. It consistently ranks in the top largest architecture/engineering and interior design firms in the US, and is listed in BD World Architecture’s top 25 global practices.