Downer Group employs approximately 33,000 people across more than 300 sites, primarily in Australia and New Zealand, but also in the Asia-Pacific region, South America and southern Africa.

[4] In 1998, Downer purchased major roads contractor Technic Group, and was first listed on the Australian Securities Exchange.

[7] In March 2017, Downer acquired Hawkins, one of New Zealand's largest builders, and in June 2017, took majority ownership of Spotless Group Holdings through a hostile takeover.

[12][13] Projects undertaken by the company have included: Downer reports its financial results under five service lines: Transport; Utilities; Facilities; Engineering, Construction and Maintenance (EC&M); and Mining.

[27] In July 2014, Keolis Downer commenced operating the G:link light rail line on the Gold Coast.

[30][31] Transport comprises Downer's road services, infrastructure projects, and rail & transit systems businesses.

[32] In June 2023, Downer Group sold the transport projects business to Gamuda Berhad who rebranded it DT Infrastructure.

Facilities businesses include Spotless, AE Smith, Alliance, Ensign, EPICURE, Mustard, Nuvo, Taylors and Envar.

[39] On 1 February 2021 Downer completed the sale of its Open Cut Mining West business to MACA Limited.

Downer's general manager of business excellence and reputation Brooke Dahlberg said "the method is safe, and it has no plan to ban staff from using it – the choice to use it was up to individual employees.