Johannes Stöffler (also Stöfler, Stoffler, Stoeffler; 10 December 1452 – 16 February 1531) was a German mathematician, astronomer, astrologer, priest, maker of astronomical instruments and professor at the University of Tübingen.
Johannes Stöffler was born on 10 December 1452, in Justingen (now part of Schelklingen) on the Swabian Alb. Having received his basic education at the Blaubeuren monastery school, he registered at the newly founded University of Ingolstadt on 21 April 1472, where he was consequently promoted Baccalaureus in September 1473 and Magister in January 1476. After finishing his studies he obtained the parish of Justingen where he, besides his clerical obligations, concerned himself with astronomy, astrology and the making of astronomical instruments, clocks and celestial globes. He conducted a lively correspondence with leading humanists - for example, Johannes Reuchlin, for whom he made an equatorium and wrote horoscopes.
In 1499 he predicted that a deluge would cover the world on 20 February 1524. In 1507, at the instigation of Duke Ulrich I he received the newly established chair of mathematics and astronomy at the University of Tübingen, where he excelled in rich teaching and publication activities and finally was elected rector in 1522. By the time of his appointment he already enjoyed a virtual monopoly in ephemeris-making in collaboration with Jacob Pflaum, continuing the calculations of Regiomontanus through 1531, and then through 1551, the latter being published posthumously in 1531.
His treatise on the construction and the use of the astrolabe, entitled Elucidatio fabricae ususque astrolabii, was published in several editions and served astronomers and surveyors for a long time as a standard work.
Philipp Melanchthon and Sebastian Münster rank among his most famous students. When a plague epidemic forced the division and relocation of his university to the surrounding countryside in 1530, Stöffler went to Blaubeuren and died there on 16 February 1531 of the plague. He was buried in the choir of the collegiate church (Stiftskirche) in Tübingen.
- 1493: A celestial globe for the Bishop of Konstanz. This globe, as the sole remaining and most important object of his workshop, is exhibited at the Landesmuseum Württemberg in the Old Castle in Stuttgart.
- 1496: An astronomical clock for the Minster of Konstanz.
- 1498: A celestial globe for the Bishop of Worms.
- 1499: An Almanac (Almanach nova plurimis annis venturis inserentia) published in collaboration with the astronomer Jakob Pflaum of Ulm, which was designated as a continuation of the ephemeris of Regiomontanus. It had a large circulation, underwent 13 editions until 1551 and exerted a strong effect on Renaissance astronomy.
- 1512 - 1514: Commentary on Ptolemy's Geography. Unpublished manuscript with comments on books 1 and 2 of the Geography, preserved at University of Tübingen; the remaining commentaries were lost in a fire in 1534.
- 1513: A book on the construction and use of the astrolabe (Elucidatio fabricae ususque astrolabii), published in 16 editions up until 1620, and, in 2007, for the first time in English.
- 1514: Astronomical tables (Tabulae astronomicae).
- 1518: A proposal for a calendar revision (Calendarium romanum magnum) which formed a foundation for the Gregorian calendar.
- 1534 (posthumously published): Commentary on the Sphaera of pseudo-Proclus (Ioannis Stoefleri Iustingensis mathematici eruditissimi, faciléque omnium principis, in Procli Diadochi, authoris grauissimi Sphæram mundi, omnibus numeris longè absolutissimus commentarius) 
- "Ten Notable Apocalypses That (Obviously) Didn't Happen". Smithsonian magazine. November 12, 2009. Retrieved 2009-11-14.
In 1499, the German mathematician and astronomer Johannes Stöffler predicted that a vast flood would engulf the world on 20 February 1524. (His calculations foretold 20 planetary conjunctions during this year—16 of which would take place in a “watery sign,” a.k.a. Pisces.)<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Gingerich, Owen (1975). ""Crisis" versus Aesthetic in the Copernican Revolution" (PDF). Vistas in Astronomy. 17 (1): 85–95. Bibcode:1975VA.....17...85G. doi:10.1016/0083-6656(75)90050-1. Retrieved 23 June 2016.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Kern, Ralf, Wissenschaftliche Instrumente in ihrer Zeit. Vol. 1: Vom Astrolab zum mathematischen Besteck. Cologne, 2010. p. 313.
- Duzer, Chet Van (2017-07-03). "The Reluctant Cosmographer: Johannes Stöffler (1452–1531) and the Discovery of the New World". Terrae Incognitae. 49 (2): 132–148. doi:10.1080/00822884.2017.1351647. ISSN 0082-2884.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Stoeffler, Johann (1553). Elucidatio fabricae ususque astrolabii. Apud G. Cavellat.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
- Alessandro Gunella and John Lamprey, Stoeffler's Elucidatio (The translation of Elucidatio fabricae ususque astrolabii into English). Published by John Lamprey, 2007. ISBN 1-4243-3502-7, ISBN 978-1-4243-3502-2
- Electronic facsimile-editions of the rare book collection at the Vienna Institute of Astronomy
- Online Galleries, History of Science Collections, University of Oklahoma Libraries – High resolution images of works by and/or portraits of Johannes Stoeffler in .jpg and .tiff format