The daughter of Romanian actor Valentin Platareanu, Alexandra Maria Lara escaped Nicolae Ceausescu's tyrannical regime with her parents when she was 4 years old to start a new life in West Germany. Initially intending to relocate to Canada, the family found themselves in Freiburg im Breisgau before ending up in Berlin.

Following in her father's footsteps, Alexandra fell under the spell of acting at an early age and appeared in a number of feature roles during her teens. Her debut came in 1994’s mini-series Stella Stellaris. After graduating high school in 1997, she studied acting until 2000 at the Theaterwerkstatt Charlottenburg, a school managed by her father.

Alexandra Maria Lara's performance in the 2001 feature Der Tunnel garnered the actress international acclaim, and she went on to make her debut in a non German-language production with the epic mini-series Napoleon (2002), featuring an all-star cast including Isabella Rossellini and John Malkovich. That same year, she appeared in the British TV movie Doctor Zhivago, which featured Keira Knightley and Sam Neill. In 2004, she portrayed Hitler's wartime secretary, Traudl Junge, in the Oscar-nominated Der Untergang.

When 2005 rolled around, Alexandra had the opportunity to visit her Eastern European homeland as a jury member at the 2005 Transylvanian Film Festival. And in 2007, she co-starred in a number of English-language films, including the comedy I Really Hate My Job with Neve Campbell; the romantic-thriller Youth Without Youth, starring Tim Roth; and the Ian Curtis biopic Control.