Tulchan hopes to tap into Fry's experience of having worked at several of the UK's biggest companies, and his CSR expertise.
He will become Tulchan's 12th top-rank consultant and gain equity in the firm, along with 17 of its 24 management and staff.
Fry, who was made redundant three months ago after five years at the FTSE 100 utility, will join in January.
As well has heading comms at one of the energy sector's biggest firms, Fry was Sainsbury's group comms director from 1996 to 2000.
Before that he led comms at Eurotunnel for two years and from 1990 held the top UK comms role at US telecommunications company AT&T.
He left Scottish Power in September after the group's £35m restructure plan resulted in the merger of the company's HR and corporate comms departments (PRWeek, 9 September).
As well as Scottish Power, Tulchan's clients include Marks & Spencer, Whitbread, Daily Mail, General Trust and Matalan.
Last week Scottish Power rejected a takeover bid by German utility Eon, which would have valued the firm at £11.3bn and created one of the largest energy suppliers in the UK.