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 world No. 6 in the WTA doubles rankings. Melichar won the major title in mixed doubles at the 2018 Wimbledon Championships with Austrian partner Alexander Peya. She has also won sixteen WTA Tour doubles titles as well as two 125 titles on the WTA Challenger Tour.
In singles, she has reached a career-high singles ranking of No. 400 in 2012 and has won two ITF titles.