Others eligible for the Class of 2016 are doubles specialist Helena Sukova, Yvon Petra and Margaret Scriven. Induction is in July.
Henin, a Belgian, won seven major singles championships, including four at the French Open. She spent 117 weeks atop the WTA rankings, finishing at No. 1 in 2003, 2006 and 2007.
Safin, a Russian, won the 2000 U.S. Open and 2005 Australian Open and was No. 1 for nine weeks.
Sukova, from the Czech Republic, won 14 Grand Slam tournament titles in women's doubles and mixed doubles. She was a four-time major finalist in singles.
Petra and Scriven were nominated posthumously in the master player category.
Petra, who died in 1984, was the last man from France to win the Wimbledon singles title, in 1946.
Scriven was the first left-hander to win a Grand Slam title, taking the French national championships - now known as the French Open - in 1933-34. Scriven, who was British, died in 2001.