Office Design Group: U.K. - Space analysis, planning, interior design and fitting out services throughout Europe
Oldershaw & DeMann Associates: Los Angeles, CA - Hospitality projects, residential interiors and product design.
Olson Sundberg Architects: Seattle, WA - Residential, Commercial, Museum, Urban design.
Omni Design Group: South Pasadena, CA - Registered Civil Engineers, Professional Land Surveyors, Architects, and Licensed Landscape Architects.

Onuma & Associates: San Luis Obispo, CA - Architecture Planning Consulting, Virtual Reality, City Planning, Master Planning, Housing, Interior Design.
Orpheus Acoustics: Lancaster, PA - Architectural acoustics consulting firm specializing in room acoustics and noise control for performance spaces, houses of worship and other critical listening environments.
TM Osborn Associates: Gaithersburg, MD - Full service architecture, facility planning and interior design firm.
Otak: Lake Oswego, OR - Planning, engineering, and architecture firm specializing in transportation, growth management and urban and community design.

Overland Partners Inc: San Antonio, TX - Architecture and planning, project management, Marketing support.
OWEN Group, Inc: Irvine, CA - Facilities Design, Infrastructure Design, Environmental Sciences, Geotechnical Engineering, Construction Management.
The OwneRep Group: Houston, TX - Architectural Design and Project Management.
Oxford Architecture: Nashville, TN - Architecture, Planning, Interior Architecture.