Watch Now


Daimler Trucks North America gets new CEO with Nielsen’s retirement

Mercedes-Benz Truck’s John O’Leary assumes leadership April 1

John O'Leary, left. will succeed Roger Nielsen as president and CEO of Daimler Trucks North America effective April 1. (Photo: Daimler)

Market leader Daimler Trucks North America (DTNA) is getting a new CEO with the retirement of current leader Roger Nielsen.

The Daimler Truck AG Board of Management appointed John O’Leary as president and CEO effective April 1. He will oversee the division that sells about four in 10 trucks in the U.S.

DTNA brands are Freightliner, Western Star, Thomas Built Buses, Freightliner Custom Chassis Corp. and Detroit Diesel Corp.

Nielsen, 60, will retire April 30 after 35 years with the company, the last four years as DTNA president and CEO. During his tenure, he declared “the future is electric” and began to get fleet customers ready for a transition to zero-emission trucks. Battery-powered versions of the Class 8 flagship Freightliner Cascadia and medium-duty Class 6 M2 are in customer tests.


DTNA will begin selling the eCascadia and eM2 to fleet customers in 2022. Currently, 38 of the trucks are in customer demonstrations. They have amassed nearly 700,000 miles of real-world driving, mostly in climate-conscious California, where regulators will begin enforcing sales quotas of trucks with no tailpipe emissions in 2024. 

The miles driven have more than doubled since August 2020.

O’Leary’s background

O’Leary, also 60, started at DTNA with Freightliner in 2000 and established internal transformation processes. He also led the U.S. school bus business as president and CEO of Thomas Built Buses. He later ran the aftermarket business as senior vice president. O’Leary became DTNA chief financial officer in 2012 and served until September 2020.

Since then, O’Leary has been the chief transformation officer for Mercedes-Benz Trucks in Germany. He also led the Mercedes-Benz Truck organization until this month.


“As CFO of DTNA and lately as chief transformation officer of Mercedes-Benz Trucks, he has proven that his experience and knowledge make him just the right person to successfully lead DTNA into the future,” Martin Daum, president and CEO of Daimler Truck AG, said in a press release.

Nielsen’s tenure

Nielsen succeeded Daum as DTNA president and CEO on April 1, 2017. He began his career in 1986 as a Freightliner manufacturing engineer responsible for wiring harness testing. Nielsen rose through management positions in manufacturing and supply chain management to become chief operating officer in 2001, a role he held until 2016.

Under Nielsen, Thomas Built Buses launched the battery-powered Jouley school bus. Daimler also made two investments in electric bus and powertrain maker Proterra Inc. Nielsen departs with DTNA controlling about 40% of the truck market in the U.S.

“Besides his passion for our business and unprecedented customer orientation, he is the embodiment of responsible people leadership,” Daum said of Nielsen.

Daimler will create standalone truck business

Proterra electrification SPAC gets Daimler Trucks investment

Daimler Trucks not sweating loss of chunks of market share 

Click for more FreightWaves articles by Alan Adler.


Alan Adler

Alan Adler is an award-winning journalist who worked for The Associated Press and the Detroit Free Press. He also spent two decades in domestic and international media relations and executive communications with General Motors.