Johan Patrik Ljungström (1784–1859) was a Swedish jeweler, inventor, and underwater diving pioneer.
Active as a jeweler and burgher in Stockholm, Uddevalla, and Saint Petersburg, Russian Empire, works surviving from his ateliers include ranging from ciboriums preserved by the Church of Sweden, to jewelry for personal adornment represented by the Nordic Museum, as well as regional cultural heritage museums.
The jewelry business started by Ljungström was with time overtaken by his descendants, remaining one of the oldest active jewelers in the region.
Subsequent to initial experiments in own ateliers with copper apparatuses and chandeliers of ink, brass and crystal, the technology was exhibitioned in the city of Uddevalla, reportedly one of the first such public installations of gas lightning in the region, enhanced as a triumphal arch for the city gate for a royal visit of Charles XIV John of Sweden in 1820.
In 1825, the bell, equipped with compass and methods of communication to the surface, successfully dived down to 25 ells with Ljungström and an assistant on board, "to the awe of the local society, much of which was assembled for the demonstration."