Constantin Andreas von Regel

Constantin Andreas von Regel (Lithuanian: Konstantinas Regelis; born 10 August 1890 in Saint Petersburg, died 22 May 1970 in Zürich) was a Russian and Lithuanian horticulturalist and botanist. He was a grandson of Eduard August von Regel.

In 1922 he was named head of the department of botany at the Kaunas University. During the following year he became director of the newly established botanical garden at Kaunas. He was the author of approximately 150 scientific books and articles, including significant works in the fields of geobotany and phytogeography.