Theatrum Orbis Terrarum (Latin: [tʰɛˈaːtrũː ˈɔrbɪs tɛˈrːaːrũː], "Theatre of the Lands of the World") is considered to be the first true modern atlas.

The publication of the Theatrum Orbis Terrarum (1570) is often considered as the official beginning of the Golden Age of Netherlandish cartography (approximately 1570s–1670s).

In the Ortelius atlas, however, the maps were all in the same style and of the same size, printed from copper plates, logically arranged by continent, region and state.

After the initial publication of Theatrum Orbis Terrarum, Ortelius regularly revised and expanded the atlas,[3] reissuing it in various formats until his death in 1598.

The online copy of the 1573 volume held by the State Library of New South Wales contains 70 numbered double-page sheets, tipped onto stubs at the centerfold, with six maps combined with descriptive letterpress on the recto of each first leaf.

[5] Theatrum Orbis Terrarum is used as the centerpiece of the Fool's Cap Map of the World, which is a satirical presentation of Europe's understanding of the globe.

This is followed by the bibliography (Catalogus Auctorum), an index (Index Tabularum), the maps with text on the back, followed (starting from 1579 in the Latin editions) by a register of place names in ancient times (Nomenclator), the treatise, the Mona Druidum insula of the Welsh scientist Humphrey Lhuyd (Humphrey Llwyd) over the Anglesey coat of arms, and finally the 'privilege' and a colophon.