The Blue Jasmine filmmaker is the 2014 recipient of the prestigious honour, but Allen, who is notorious for shunning awards shows, is not planning to attend the ceremony.
Members of the Hollywood Foreign Press Association, who nominate and vote on the awards, have now decided to ask Keaton to accept the award on his behalf, according to Deadline.com.
Keaton and Allen met in 1968 when she was cast in his Broadway production, Play it Again, and she appeared in eight of his films over the course of two decades. They also dated for five years.
Previous recipients of the top honour include Jodie Foster, Morgan Freeman, Harrison Ford, Audrey Hepburn, Robert De Niro, Al Pacino, Martin Scorsese and Steven Spielberg.
The 71st Annual Golden Globe Awards will be held in Los Angeles on 12 January (14).