Ana Cristina Cardoso Dias Mesquita was born in Portugal's second city of Porto on 22 March 1979.

She lived most of her youth in the town of Rio Tinto in the municipality of Gondomar, north of Porto.

Mesquita obtained a degree in archaeology and history from the University of Coimbra and became a practising archaeologist in 2009.

A member of the Portuguese Communist Party (PCP), she was elected in 2015 as a deputy to the 13th Legislature of the Assembly of the Republic, representing the Lisbon constituency.

In January 2021, she was chosen as one of two of the 10 PCP parliamentarians to be given priority access to COVID-19 vaccine, because of the importance of the role she played in the Assembly.