ACNielsen was established in the United States in 1923 by Arthur C. Nielsen, Sr., one of the founders of the modern marketing research industry. Among many innovations in consumer-focused marketing and media research, Mr. Nielsen was responsible for creating a unique retail-measurement technique that gave clients the first reliable, objective information about competitive performance and the impact of their marketing and sales programs on revenues and profits. Nielsen information gave practical meaning to the concept of market share and made it one of the critical measures of corporate performance. Mr. Nielsen also founded the business known today as Nielsen Media Research, the global leader in television audience measurement and other media research services.

ACNielsen opened its first international office in the UK in 1939 and, after World War II, progressively expanded its operations in Western Europe, Australia and Japan. The company increased its presence in Asia Pacific in 1994 by acquiring Survey Research Group, and in the Middle East and Africa in the late 1990s through the acquisition of AMER World Research.

In 2001, ACNielsen became part of VNU, a world leader in marketing information, media measurement and information and business media.

In 2003, VNU announced a new organizational structure for VNU Marketing Information (MI), its largest business group, to address evolving client needs and to create an enhanced platform for accelerated growth. The new structure includes the creation of VNU Advisory Services (which includes sister MI companies BASES, Spectra, Claritas, and HCI), a dedicated unit that will draw on the resources of the entire MI group and other VNU businesses, along with third-party capabilities, to develop new, integrated services and a new approach to client service.

In 2005, VNU attempted to expand into healthcare and pharmaceutical information by acquiring IMS Health. Although the merger was terminated in the face of shareholder opposition, the two companies agreed to work together to develop new capabilities.

In 2006, VNU was acquired and taken private by a consortium of six private equity firms.

In 2007, VNU changed its name to The Nielsen Company.  This new identity emphasizes its best known brand name and underscores its commitment to create an integrated, streamlined global organization.