Founded in 2010, Brennan Investment Group is a privately held real estate investment firm headquartered in Rosemont, Illinois. The company was established by Michael Brennan, former CEO of First Industrial Realty Trust, and has since grown into one of the largest private owners of industrial real estate in the United States. Brennan specializes exclusively in industrial assets, with a portfolio strategy that spans acquisition, development, and redevelopment across major metropolitan markets. The firm’s investment philosophy centers on value-add and opportunistic strategies, often targeting infill locations and corporate surplus properties. Brennan co-invests with both institutional and private capital partners, aiming to deliver strong risk-adjusted returns. Its asset class focus includes single-tenant net lease, multi-tenant light industrial, industrial outdoor storage (IOS), and data centers. Brennan’s portfolio comprises approximately 57 million square feet across 604 properties in 29 states, with recent expansion into logistics and adaptive reuse projects.