Editing 1809 in science (section)

==Births==
* January 4 – [[Louis Braille]] (died [[1852 in science|1852]]), French [[inventor]].
* January 6 – [[Marie Durocher]] (died [[1893 in science|1893]]), Brazilian physician.
* February 12 – [[Charles Darwin]] (died [[1882 in science|1882]]), English [[Natural history|naturalist]].
* February 15 – [[Cyrus McCormick]] (died [[1884 in science|1884]]), American inventor.
* February 21 – [[Carl Ernst Bock]] (died [[1874 in science|1874]]), German [[physician]] and [[anatomist]].
* April 7 – [[James Glaisher]] (died [[1903 in science|1903]]), English [[meteorologist]] and balloonist.
* April 15 – [[Hermann Grassmann]] (died [[1877 in science|1877]]), German [[mathematician]].
* April 20 – [[James David Forbes]] (died [[1868 in science|1868]]), Scottish physicist, glaciologist and seismologist.
* August 29 – [[Oliver Wendell Holmes Sr.]] (died [[1894 in science|1894]]), American physician and writer.
* November 22 – [[Bénédict Morel]] (died [[1873 in science|1873]]), French [[psychiatrist]].
* Date unknown – [[William Lobb]] (died [[1864 in science|1864]]), English plant collector.