 William Hurt was initially offered the role of Alan Grant , but turned it down without reading the script . Harrison Ford was also offered the role of Grant . Sam Neill was ultimately cast as Grant three or four weeks before filming began . Neill said that " it all happened real quick . I hadn 't read the book , knew nothing about it , hadn 't heard anything about it , and in a matter of weeks I 'm working with Spielberg . " Janet Hirshenson , the film 's casting director , felt that Jeff Goldblum would be the right choice to play Ian Malcolm after reading the novel . Jim Carrey also auditioned for the role . According to Hirshenson , Carrey " was terrific , too , but I think pretty quickly we all loved the idea of Jeff . " 
