Nicole Melichar-Martinez (née Melichar; Czech: Nicole Melicharová, Czech pronunciation: [ˈmɛlɪxarovaː]; born July 29, 1993) is an American professional tennis player who specializes in doubles. On 3 July 2023, she peaked at No. 6 in the WTA doubles rankings. Melichar has won fifteen doubles titles on the WTA Tour and two WTA Challenger doubles titles as well as seven doubles titles on the ITF Circuit. She also has won one major title, winning the mixed-doubles competition at the 2018 Wimbledon Championships with Austrian partner Alexander Peya.
In singles, she has reached a career-high singles ranking of world No. 400 in 2012 and has won two ITF titles.