Astronomiæ Instauratæ Mechanica: Digital edition of orignal book, with illustrations and introduction.
Brahe, Tycho: Link collection, mainly biographies.
Eric Weisstein's Treasure Trove of Scientific Biography: Brahe, Tycho: Short article with references.
MacTutor History of Mathematics: Tycho Brahe: Short article of his life and work.
Neft's AstroScientific Tycho Brahe Homepage: Lifehood and his list of bad luck days known as "Tycho Brahian" days.
Rundetaarn: Tycho Brahe: Concise timeline of his life and accomplishments.
The Astronomical Instruments of Tycho Brahe: Exhibition from The Royal Library in Copenhagen. Includes scanned book pages, links and bibliography.
The Galileo Project: Tycho Brahe: Bibliographical essay.
The Noble Dane: Images of Tycho Brahe: An exhibition at the Museum of the History of Science, Oxford.
Tycho Brahe: About his achievements, life and world system. From the Swedish society Tycho Brahes Glada Vänner.
Tycho Brahe - official website: About his life and scientific work. Presented by the city of Landskrona.
Tycho Brahe and Johannes Kepler: Short biographies. Lecture notes from the course "Galileo and Einstein".