The appointment is designed to boost its relationships with, and reputation among, UK audiences such as the NHS, regulators and local communities.
It comes as Pfizer, which makes drugs such as Viagra and cholesterol-buster Lipitor, plans further recruitment to a newly created UK CR team.
Luker joins from management consultant First& 42nd, an Edelman subsidiary, where she ran the London CR practice. The creation of her role comes as the pharma sector faces increasing scrutiny from regulators and the media.
Although Pfizer has avoided negative coverage of the scale attracted by US rival Merck over its anti-arthritis treatment Vioxx, it has nonetheless had to cope with the lower-profile withdrawal of its painkiller Bextra.
Luker will not deal with product-related issues, but will concentrate on community-related and philanthropic initiatives.
She said: 'I aim to identify areas of good practice, such as Pfizer's employment practices, and create a UK CR strategy. We want to integrate CR more across the company.'
Luker heads a four-strong team including CR manager Emma Cornish, who joined in May from the World Nuclear Association. She is now recruiting for a further CR manager.
Luker formerly spent five years at Regester Larkin. Prior to that she was at GCI.
She is based in Pfizer's UK HQ in Surrey, and reports to UK corporate and PA director Colette Goldrick.