Geheimrat Julius Wilhelm Theodor Curtius (27 May 1857 – 8 February 1928) was professor of Chemistry at Heidelberg University and elsewhere.

He published the Curtius rearrangement in 1890/1894 and also discovered diazoacetic acid, hydrazine and hydrazoic acid.In 1882 he carried out the first ever peptide synthesis, creating the N-protected dipeptide, benzoylglycylglycine[1] Theodor Curtius was born in Duisburg in the Ruhr area in Germany.

In 1894 he founded the Kiel section of the Association of German and Austrian Alpinists, which he personally supported with gifts.

In his Munich period, he became a close friend of the alpinist guide Christian Klucker, with whom he made mountaineering hikes for many years thereafter.

The Heidelberg University Archives has, in its possession, a photo album from 1907 marking the 25th anniversary of Theodor Curtius receiving his Doctorate.