|Headquarters||Boston, Massachusetts (HQ)|
|Number of locations||12 offices in 10 countries|
|Key people||Pam Hamlin (Global President, Arnold Worldwide)
Wade Devers (Executive Creative Director, Arnold Boston)
Pete Johnson (Executive Creative Director, Arnold Boston)
Lisa Unsworth (Chief Marketing Officer, Arnold Worldwide)
Matt Howell (Global Chief Digital Officer)
Arnold Worldwide is an advertising agency headquartered in Boston, Massachusetts. The agency has 12 offices in 10 countries, including Boston, Lisbon, London, Madrid, Milan, New York, Prague, São Paulo  Shanghai, Sydney, Toronto and Washington DC. The agency is part of Havas, a global advertising holding company based in France.
Arnold Rosoff founded Arnold Worldwide, formerly Arnold & Co. and Arnold Communications, in 1946. Rosoff continued to serve as chairman until his retirement in 1986. Upon retirement, Rosoff sold the agency to his employees. Ed Eskandarian acquired the agency in 1990.
Eskandarian grew Arnold "through about a dozen acquisitions". In 1995, Eskandarian, a former partial-owner of the Boston Red Sox, sold Arnold to Snyder Communications. Havas acquired Snyder Communications in 2000.
Advertising Age ranked Arnold as the 19th largest American agency in 2005 with revenues of $114m. A year later, Advertising Age listed Arnold Worldwide as the 28th largest American agency with revenues of just under $90m. According to Adweek, Arnold Worldwide's revenue in 2009 was estimated at $235m.
After struggling to gain accounts earlier in the year, Arnold Worldwide won the Panasonic account at the end of 2009. The agency hired Andrew Benett as CEO in February 2010 and had won eighteen new client accounts by the end of the year, earning them the "2010 Comeback Agency of the Year" title from Ad Age. In 2011, Ad Age chose Arnold as one of 10 agencies to be included on its annual Agency A-List. The Delaney Report, an industry newsletter, declared Arnold Worldwide "Best Ad Agency in the Nation" for the third quarter of 2010 as a result of their "strong new business track record."
Eskandarian retired at the end of 2010.
Arnold Worldwide, along with Crispin Porter + Bogusky created work for truth, the largest and most successful youth smoking prevention campaign in the country. In 2009, a reader poll conducted by Adweek named truth the campaign of the decade. Arnold's work for truth has picked up two Emmy Awards.
Arnold Worldwide is the agency behind Progressive's "Superstore" campaign featuring Flo. Flo has appeared in more than 50 TV spots since the campaign's 2008 launch, Entertainment Weekly's readers named Flo "Advertising's Greatest Icon" on February 6, 2011.
Arnold Worldwide created the "Drivers wanted" campaign for Volkswagen of America with the slogan “On the road of life there are passengers and there are drivers. Drivers wanted.” The slogan is the most recognized in the American automotive industry. The campaign launched in 1995 and was the driving force behind Volkswagen's ad campaigns for more than a decade.
- Diaz, Johnny. Advertising Itself Boston Globe, November 24, 2010.
- Penteado, Claudia and Laurel Wentz. Brazil Drawing in Ad Agencies from Around the Globe Ad Age, December 6, 2010.
- "Havas Business Unit". Havas.com.
- Warner, Judy (March 30, 1998). "Arnold, Snyder Do The Deal". AdWeek.
- Healy, Beth. Minority Owner Selling Stake in Red Sox Boston Globe, May 27, 2009.
- Gianatasio, David. Ex-Ad Exec Arnold Rosoff Dies Adweek, November 20, 2009.
- Ad Age Staff. 2006 Agency Report Advertising Age
- Ad Age Staff. [agencyprofilesyearbook07 s.qxp 2007 Agency Report] Advertising Age.
- Gianatasio, David and O’Leary, Noreen. Panasonic Selects Arnold Adweek, December 29, 2009.
- Parekh, Rupal. Arnold Names Euro's Benett as First Global CEO Advertising Age, February 17, 2010.
- Parekh, Rupal. Arnold is Ad Age's 2010 Comeback Agency of the Year Advertising Age, January 24, 2010.
- "ACTUAL ARTICLE TITLE BELONGS HERE!". Bloomberg BusinessWeek. Reuters. September 15, 2010.
- Cassidy, Anne. Arnold Ties with Euro RSCG KLP to Boost 'Micro-Network' Brand Republic, September 30, 2010.
- Gianatasio, David (November 20, 2009). "Ex-Ad Exec Arnold Rosoff Dies". Adweek.
- "The Emmy Awards 2006". Emmyonline.org.
- "truth Advertising Campaign, Shards O' Glass, Takes Home Emmy". Tobacco.org.
- Elliot, Stuart. A Nomadic Insurance Pitchman, Luring New Consumers, The New York Times, November 30, 2010.
- Ward, Kate. Big Shill Final: And the Winner Is... The Progressive Girl! Entertainment Weekly, February 6, 2011.
- "News Wire". Adweek. March 28, 2011.
- Kelly, Francis J. III, Barry Silverstein. The Breakaway Brand: How Great Brands Stand Out, Chapter 5