Millmore has worked with the firm since 2005 as a consultant but has decided to return to full-time fee earning.
He specialises in IP litigation and also advises on related commercial matters such as licensing, joint ventures and patent and brand portfolio creation and exploitation. His clients include Hat Trick Productions, Universal Music and The Disctronics Manufacturing Group.
Millmore spent 10 years as a partner at Macfarlanes and left in 1999 to run an IP strategy firm.
Lawrence Abramson, Harbottles managing partner, said: “Andy has worked with us for some time as a consultant providing strategic, commercial and litigation advice to a range of clients. We are delighted that he has agreed to join us full time as a partner and we look forward to working with him in the years to come.”