Cecilia Raquel Costa Melgar (born 26 December 1992) is a Chilean former tennis player.
Costa Melgar won four singles titles and seven doubles titles on the ITF circuit.
On 20 May 2013, she reached her best singles ranking of world number 367.
On 8 September 2014, she peaked at world number 216 in the doubles rankings.
Since her debut for Chile in 2010, Costa Melgar has a 15–6 record for her country in Fed Cup competition.