Michael Hammer is a fictional character created by the American author Mickey Spillane. Hammer debuted in the 1947 book I, the Jury, and appeared in 13 novels by Spillane (the final published 1996), and 15 more published by Max Allan Collins after Spillane's death and based on Spillane's notes or incomplete manuscripts.
Spillane's Mike Hammer books were immensely successful in the 1950s, and Spillane's books rank among the best-selling fiction in modern publishing history with estimated sales over 100 million to 200 million.