Berta Geissmar (14 September 1892 Mannheim – 3 November 1949 London) was the secretary and business manager for two prominent orchestral conductors, Wilhelm Furtwängler and Sir Thomas Beecham. From 1922 until 1935, Geissmar worked for the Berlin Philharmonic Orchestra and Furtwängler, including planning and organising foreign tours for the orchestra. Because of her Jewish heritage, she was forced to leave the post and her native Germany in late 1935. Fleeing to London, she gained a similar position with Thomas Beecham and the London Philharmonic Orchestra. She continued in this position until shortly before her death.