Sarah Cullen is the Founder and CEO of SideCar Public Relations, a full-service communications firm operating at the intersection of economic development, commercial real estate and placemaking. With a deep understanding of the built environment and a belief in the power of relationships, Sarah founded SideCar in 2011 to help clients shape the stories, trust and visibility needed to move projects and communities forward. Since its inception, the firm has partnered with developers, cities, architects and organizations working on transformative developments, public-private partnerships, and complex civic engagement efforts across Colorado and beyond.
Under Sarah’s leadership, SideCar has built a reputation for delivering strategic, results-driven communications tailored to the realities of fast-paced, highly scrutinized industries. The firm provides integrated, in-house expertise across public relations, social media, stakeholder engagement, events, branding and digital communications, allowing clients to benefit from holistic strategies that align messaging, reputation and long-term goals. Sarah’s approach emphasizes proactive counsel and the power of connections, helping clients navigate challenges, build credibility, and sustain momentum over time.
Over the last decade, Sarah has grown SideCar into a 13-person firm supporting more than 65 clients representing the public, private and nonprofit sectors. The firm was named 2025 Boutique Agency of the Year by the Colorado chapter of the Public Relations Society of America, recognizing its strategic growth, integrated service model, and strong culture. SideCar has also been named one of the best PR agencies in the country by Forbes, affirming its national reputation and leadership in communications for the built environment. Sarah has personally been recognized for her leadership and impact with honors including Denver Business Journal’s 40 Under 40, Bisnow Denver’s CRE Power Women and selection as a Titan 100 honoree.
An influential member of Denver’s business and civic community, Sarah is passionate about using communications as a tool to build understanding, foster collaboration, and elevate the people shaping our cities. She currently serves on the Downtown Denver Partnership’s Urban Exploration (Urban X) Committee and Economic Development Committee, as well as on the Board of Governors. She additionally contributes to the National Western Stock Show and has supported organizations including the Urban Land Institute and the Colorado Women’s Chamber of Commerce through mentorship and leadership initiatives.
Prior to founding SideCar, Sarah worked at JohnstonWells Public Relations, where she supported clients in the real estate, nonprofit, telecommunications, retail and healthcare sectors. She is a proud graduate of Colorado State University with a bachelor’s degree in speech communication and a concentration in media relations. Sarah also holds a master’s degree in Organizational Leadership from CSU Global. Outside of work, Sarah enjoys spending time with her family, traveling, skiing, hiking with their dogs, fly fishing and trail riding with her horses.
