From the experts:
In the eighteenth century there was a poetic fad for names with the 'inda' sound, and, along with Belinda, Clarinda, Dorinda and Florinda, Melinda was one of those created at that time. It came into non-literary use in the 1840's, peaking in the U.S. in the late 1960s and 1970s: Melinda was a Top 100 name from 1967 to 1980. It began to fade as nickname Mindy ascended. Nowadays, however, Melinda feels more contemporary than cousins Melissa, Mindy, Belinda and Linda.
Melinda was the name of the lead character played by Jennifer Love Hewitt in Ghost Whisperer; her most prominent modern bearer is philanthropist Melinda Gates.