John O’Leary to Succeed Roger Nielsen as CEO of DTNA

John O'Leary and Roger Nielsen
John O’Leary (left) follows Roger Nielsen, who retires after 35 years at Daimler Trucks North America, the last four years as its president and CEO. (DTNA)

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Daimler Truck AG has appointed John O’Leary as the next president and CEO of Daimler Trucks North America, the leading truck maker in North America, effective April 1.

O’Leary succeeds Roger Nielsen, who will retire April 30 after 35 years with the Portland, Ore.-based company, the last four as president and CEO.

O’Leary served as chief transformation officer for Mercedes-Benz Trucks in Stuttgart, Germany, since September 2020. Before that, he was chief finance officer at DTNA, which he joined in 2000 from Paccar Inc.

“This is probably the easiest and smoothest transition I could ever imagine, having John come in,” Nielsen said in an interview with Transport Topics. “For the last four years, he has been my partner in running this business. I rely on John for everything on that [financial] side of the house.”

The two met in May 2001 when they were tasked with managing the turnaround at Freightliner Corp., as the company was known then. 

Freightliner had gone after an increased market share in the mid-1990s, guaranteeing high residuals on used trucks. By the late ’90s, the truck market was booming. There were zero-down loans to be had. Then the economy crashed along with used truck values. Freightliner was losing millions of dollars, when Nielsen and O’Leary went to work.

Over the years, the two became fast friends, Nielsen said.

They continued to work together when O’Leary was president of Thomas Built Buses, then when he was senior vice president of aftermarket — where his office was next to Nielsen’s — and then when he took over as chief finance officer. 

“He is an absolutely top-notch businessman,” Nielsen added. “He knows the products well, knows the customers well and has a heart for customers unlike anybody I’ve ever known. So for me, the transition is as easy as ‘Hey John, I’ve moved out. Come on, move in. Let’s go.’ ”



“In addition to his longtime experience in the North American truck business,” said Martin Daum, CEO at Daimler Truck AG, “John O’Leary, in his time as chief finance officer of DTNA, has proven that his experience and knowledge make him just the right person to successfully lead DTNA into the future.”

DTNA’s brands are Freightliner Trucks, Western Star Trucks, Thomas Built Buses, Freightliner Custom Chassis Corp. and engine maker Detroit Diesel Corp.

“At the same time I would like to extend my heartfelt gratitude to Roger Nielsen for his dedication to the success of DTNA and his successful positioning of our brands Freightliner, Western Star and Thomas Built Buses,” Daum said. “Besides his passion for our business and unprecedented customer orientation, he is the embodiment of responsible people leadership.”

Nielsen began his career in 1986 as a Freightliner manufacturing engineer responsible for wiring harness testing, followed by management positions in manufacturing and supply chain management, and as chief operating officer from 2001 to 2016.


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As CEO, Nielsen started several customer trials with the Freightliner eCascadia and eM2 and launched the Thomas Built Buses Jouley school bus to pave the way to CO2-neutral transport at DTNA, according to the company. In addition, he renewed the Western Star product lineup and the vocational truck business, and made DTNA the most successful truck original equipment manufacturer in the United States.

Asked if his route to the top still was viable. Nielsen said he hoped a manufacturing engineer hired out of college now could become the CEO in 35 years.

“In manufacturing engineering, you learn everything about the product. You learn how to build them [and] how they are designed, and you meet everybody working in the communities,” he said. “And every day you met with customers at the factories. There can’t be a better training ground than someone supporting the production, delivery and launch of new vehicles.”

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