Johannes Burchart I (1546-1616), born János Both Bélaváry de Szikava (Hungarian: Szikavai és Bélaváry Both János), was a Baltic German pharmacist and druggist and the first of a line of doctors and pharmacists who owned the Raeapteek in Tallinn, Estonia, from 1582 to 1911. He was also lord of Haabneeme and Wannamois, close to Tallinn.
He was born in Pozsony in the Kingdom of Hungary, son of Ambrose, where his ancestors were lords and barons of the kingdom of Hungary, including John Both de Bajna (d. 1493), ban of Croatia.
János (Johann) left the kingdom of Hungary after the in 1575, after which Stephen Báthory ascended the throne of Transylvania and proscribed supporters of Gáspár Bekes. He took refuge successively in Salzburg (1575-1578) and Munich (1578-1580), then went to Jelgava in Latvia, and finally settled in Tallinn, then in the kingdom of Sweden, in 1580 under the name Burchart. With the permission of the Council of Tallinn, he became on 30 April 1583 the official pharmacist of the city by taking over the Raeapteek, founded by the city in around 1420.