Who is the owner of lamar advertising? Key people. Lamar Advertising is an outdoor advertising company which operates billboards, logo signs, and transit displays in the United States and Canada. The company was founded in 1902 by Charles W. Lamar and J.M. Coe, and is headquartered in Baton Rouge, Louisiana.Where can i find contact information for lamar? Contact information is available on the local websites. We have National Sales offices in New York, Los Angeles and Chicago. To purchase advertising space across multiple markets, please contact our National Sales team at (225) 218-2620 or [email protected]. Lamar supports various nonprofit organizations by donating advertising space for PSAs.What is the phone number for accesslamar advertising company? Lamar Advertising Company 5321 Corporate Blvd. Baton Rouge, LA 70808 Phone: (888) 308-5060 Business Hours: Monday - Friday, 8:00 am - 5:00 pm CSTWho is the largest outdoor advertising company? Our Company. Founded in 1902, Lamar Advertising Company (Nasdaq: LAMR) is one of the largest outdoor advertising companies in the world, with more than 348,000 displays across the United States and Canada.