As a result of the cash injection, senior directors Andrew Tharme and Chris Sinclair become joint managing directors.
The financial backing will be used to grow the agency's research team and expand and enhance its research offer.
Curtis, a former CEO of TRBi and Maritz.TRBi, has more than 30 years of research experience and brings a wealth of knowledge to Oxford Research. He is also a former head of strategy at Aegis-owned Synovate.
Curtis said: "It has some of the best clients in the business and is led by a young and innovative management team with a proven track record. With this investment, The Oxford Research Agency has a very bright future ahead of it."
The agency already has 50 staff and last year it conducted over £6m worth of research covering FMCG, transport, education, local government and retail research.
Sinclair said: "The Oxford Research Agency is a fantastic agency with an enthusiastic and committed group of researchers, providing some of the best research available. We are excited and thrilled with this opportunity to grow and enhance the business, and continue to provide our clients with ground-breaking research. With the investment in place, and with Laurence joining the agency, we aim to be the agency of choice for both researchers and clients alike."