Tennant, who was born in Bathgate and brought up in Paisley, played the main role in the hit cult television series between 2005 and 2010.
McCoy, who was born and brought up in Dunoon, starred as the Doctor from 1987-89 and in one-off shows in 1993 and 1996.
They will feature alongside the nine other actors who have played the doctor on the 11 stamps created by the Royal Mail.
Doctor Who, which follows the sci-fi adventures of the time travelling Time Lord, is the longest-running science fiction series in the world, with the first episode broadcast on November 23, 1963.
The other actors to have played the role are Matt Smith – the present Doctor – Christopher Eccleston, Paul McGann, Colin Baker, Peter Davison, Tom Baker, Jon Pertwee, Patrick Troughton and the first doctor, William Hartnell.
The stamps launch on March 26, but fans can pre-order by registering at: www.royalmail.com/doctorwho.