Johann Jacob Vitriarius (8 June 1679 - 12 December 1745)^[1][2] was a Dutch jurist of German descent.

Johann Jacob Vitrarius was the son of the German jurist Philipp Reinhard Vitriarius, who between 1675 and 1682 taught law at the Geneva Academy.^[3] At the age of 2 or 3 he moved to Leiden in the Dutch Republic when his father became professor at Leiden University. Eventually, Vitriarius studied law at the same university, earning a doctorate there in 1701 with the thesis Disputio juridica inauguralis de acquisitione rerum originaria.^[1][2]

Vitrarius became a professor of law at Heidelberg University in 1706 ^[2] and was appointed to the law faculty at Utrecht University on 4 June 1708, commencing on 17 September 1708.^[1] During 1714-15 he was Rector Magnificus at Utrecht. He left Utrecht in 1719 to take up a position at Leiden.^[1] Here he took the place of his father, and was equally widely acclaimed, particularly by the German students who at that time often studied at Dutch universities.^[3] He taught at Leiden until 15 January 1720.

Vitrarius died on 12 December 1745 in Leiden, aged 66.^[1][2]

• Annotati ad Grotii de jure belli ac pacis libros tres, 1724
• Annotata ad Sam. Stryckii examen juris feudalis. XVIII century, 1724
• Notes on Roman Law, Alexander Boswell, 1724 , 1724
• Observationes in Hugonem Grotium de Jure Belli ac Pacis. 1728-29, Alexander Boswell, 1724
• Phil. Reinh. Vitriarii ... Institutiones Juris Naturae et Gentium ... ad Methodum Hugonis Grotii conscriptae, Leiden, Apud Samuelem Luchtmans, 1734; with Johann Franz Buddeus's Historia juris naturalis, Synopsis juris naturalis & gentium ..., ut & Specimen jurisprudentiae historicae.
• Oratio funebris in obitum ... Antonii Schultingii, Halae Magdeburgicae, 1734