Gallagher Security | 39,584 followers on LinkedIn. Trusted to protect what matters most for more than 20,000 customers, in over 140 countries. | Gallagher Security is a global leader in integrated technology solutions that help organizations around the world protect, secure, and manage people and assets. Our award-winning solutions are trusted by government, defense, commercial, industrial, healthcare, transportation, mining, and educational organizations in 140 countries. We design and manufacture a comprehensive suite of security software and hardware - including integrated access control, intruder alarm, and perimeter solutions - all on site at our global headquarters.