Elfriede Lohse-Wächtler (born Anna Frieda Wächtler; 4 December 1899 – 31 July 1940) was a German painter of the avant-garde whose works were banned as "degenerate art", and in some cases destroyed, in Nazi Germany.

She became mentally ill and was murdered in a former psychiatric institution at Sonnenstein castle in Pirna under Action T4, a forced euthanasia program of Nazi Germany.

Elfriede Lohse-Wächtler grew up in a middle-class family, but left at the age of 16 to study at the Royal Arts School Dresden from 1915 to 1918 (fashion, then applied graphics).

In 1926, Elfriede Lohse-Wächtler joined the Federation of female Hamburgian artists and art lovers; in 1928. she was able to participate in some exhibitions of the New Objectivity.

During the two months' stay she painted the Friedrichsberg heads, a piece of work consisting of about 60 drawings and pastels, mainly portraits of fellow patients.

In December 1935, she underwent a forced surgical sterilisation in the Dresden-Friedrichstadt women's hospital on the grounds of Nazi eugenicist policies.

In 1940 she was deported to the former psychiatric institution at Pirna-Sonnenstein (located in the Sonnenstein castle in Pirna), where, on 31 July, she was murdered along with the majority of the other residents as part of the Nazi "euthanasia" program, Action T4.

As part of the "degenerate art" campaign by the Nazis, nine of her works from the art museum Hamburger Kunsthalle and the Altonaer Museum were confiscated and destroyed in 1937, including paintings entitled Strassen-Musik, In der Kneipe, Aus St Pauli, Café, and Cabarett,[1] as well as a large part of her paintings from Arnsdorf.