Hans Jakob Notz (Heidelberg, 15 December 1891 – Geneva, 1967) was a German-born Swiss Esperantist.
In 1920 Jakob became the director of the central office of UEA; he cared after the publication of Jarlibroj and after the magazine Esperanto.
After the reunification of the two associations, in 1947, he joined the governing council of the reborn UEA and started caring after the magazine.
In 1955 he resigned from all the posts as a form of protest, but he was nevertheless awarded the title "honorary redactor".
In 1960 the governing council of UEA learnt that Jakob had been unduly taking some money from the association; a years-long judicial procedure followed suit.