Miriam Lahnstein (born 9 August 1974 in Düsseldorf, Germany) is a German actress and psychologist.
In 1995, Miriam came to the Das Erste-Soap Verbotene Liebe. She played the villain Tanja von Anstetten from 1995 until 1998. She later reprised the role for a short period in 2001; later in April 2004 she rejoined the show until March 2007, when she left the series because of her second pregnancy. She returned later in 2007 and remained part of the soap opera until its cancellation in 2016, with the exception of a short hiatus in early 2010.
From 2003 to 2004 she played the recurring villain role of Sabine Huber in the soap Marienhof. She has also made guest appearances in many popular German television series.