Marissa Lourdes Mercado Andaya (born Marissa Lourdes Lirio Mercado; March 7, 1969 – July 5, 2020) was a Filipina politician who served as congresswoman for Camarines Sur's 1st congressional district from 2019 until her death in 2020.

In the 2019 elections, she ran as congresswoman for Camarines Sur's 1st district and emerged victorious with 61,480 votes against her sole opponent, Long Mejia, who received 29,228 votes.

She took over the position from her term-limited husband, who, in turn, ran for governor of Camarines Sur but was unsuccessful.

Mercado-Andaya was diagnosed with cancer, and her symptoms reemerged in 2020.

On July 5, 2020, she died at the age of 51 in Naga City, Camarines Sur.