Born in Madrid, María Martínez has developed most of her career in European countries and the United States. After studying at Trinity College, London and the Musikhochschule in Cologne, Germany, she completed her studies at Indiana University, USA, under Janos Starker, where she also served as an associate professor in his department. She later continued her studies with Colin Carr, becoming his assistant at Stony Brook University in New York. Simultaneously, she specialized in historically informed performance, greatly influenced by Bruno Cocset and Anner Bylsma.

She is the regular cellist of Tiento Nuovo & Ignacio Prego, with whom she was recently awarded a Diapason d'Or for their latest recording. She also collaborates with ensembles such as Música Boscareccia & Andoni Mercero, the Orquesta Barroca de Salamanca, and La Spagna.

María has performed at prestigious festivals, including the Scottish Cello Festival, Cheltenham Music Festival, Saint Martin-in-the-Fields in London, Blackheath Halls, Schleswig-Holstein Musik Festival, the CNDM Series at the Auditorio Nacional de Música in Madrid, Musika-Musica Festival at the Euskalduna Palace, and the Juan March Foundation, among others.

She has shared the stage with renowned artists and ensembles such as Yo-Yo Ma, the Emerson String Quartet, Steven Isserlis, Maurice Steger, and Cecilia Bercovich, and has performed under the baton of conductors such as Riccardo Muti, Clifford Colnot, Juanjo Mena, Jaap van Zweden, Harry Bicket, and Pablo Heras-Casado. She has led the cello section of orchestras such as the Navarra Symphony Orchestra and the ORCAM, among others. She was also a member of the Civic Orchestra of Chicago (the training orchestra of the Chicago Symphony Orchestra) and has given recitals and solo concerts on tours across China, Europe, and the United States.

She is currently a cello professor at the Royal Conservatory of Music in Madrid and has previously taught at the Centro Superior Katarina Gurska.