It operates primarily in the defence, security and critical national infrastructure markets and run testing and evaluation capabilities for air, land, sea and target systems.

As a private entity, QinetiQ was created in April 2001; prior to this its assets had been part of Defence Evaluation and Research Agency (DERA), a now-defunct British government organisation.

While a large portion of DERA's assets, sites, and employees were transferred to QinetiQ, other elements were incorporated into Defence Science and Technology Laboratory (DSTL), which remains in government ownership.

The privatisation process was subject to an inquiry by the UK's National Audit Office, which was critical of the generous incentive scheme available to the company's management.

QinetiQ has completed numerous acquisitions of defence- and technology-related companies, primarily those that are based in the United States, and is a trusted supplier to the US government.

QinetiQ USA operates under a Special Security Arrangement[3] which allows it to work independently and separately on some of the most sensitive United States defense programs despite its foreign ownership.

At the time, Moonie stated that the entity would remain a British business, being based in the UK, and that the Ministry of Defence (MoD) would retain a 'special share' in the company, while safeguards would be in place to prevent conflicts of interest.

[7] By April 2002, while QinetiQ had taken steps to operate on a commercial basis and saw third parties as its key growth area, 80% of its annual sales was reportedly being derived from the UK MoD.

[10] In late 2002, the Carlyle Group, an American private equity firm, publicly declared its intention to purchase a large stake in QinetiQ.

[16] In early August 2005, the company announced it would acquire Apogen Technologies, Inc., pending regulatory approval; according to QinetiQ's website, the purchase came at a cost of $288.0m (£162.7m).

[18] In October that year, it acquired Broadreach Networks Limited, a supplier of Wi-Fi internet equipment to the European rail industry,[19] and in February 2006, it bought Graphics Research Corporation Ltd, developer of the Paramarine software suite of ship and submarine design tools.

[28] Speculation that a consortium including QinetiQ was about to win a £10bn MoD training contract helped push their share price back above 190p in early November 2006.

It was announced on 17 January 2007 that the QinetiQ-led Metrix consortium was the preferred bidder for package one of the MoD's Defence Training Rationalisation programme, worth approx £16bn.

The role of QinetiQ's management in negotiating terms with the Carlyle Group while the private equity company was bidding for the business was also criticised by the NAO.

[31] However, the Ministry of Defence defended the sale: In January 2007, the company bought Analex, a US corporation that provides high technology professional services, principally to the US government and its agencies.

[37] In March 2007, QinetiQ spun off a new company, Omni-ID Ltd; this entity specialises in the commercial opportunities for passive UHF radio-frequency identification (RFID) tags.

[42][43] In November 2022, it was announced QinetiQ had completed the acquisition of the McLean-headquartered provider of cybersecurity and data analytics software to US government agencies, Avantus Federal for $590 million USD.

During 2005, QinetiQ was accused by union officials of its employees exhibiting higher than average levels of stress-related depression, a finding that was strongly denied by the company.