Levinus Warner, (c. 1618 – 22 June 1665) was a German-born Orientalist, manuscript collector and diplomat for the Dutch Republic in the Ottoman Empire.

Following his secondary education at the Paedagogium or Altes Gymnasium in Bremen he attended the Athenaeum Illustre there in 1636, where he received instruction from its headmaster Ludovicus Crocius, from whom he developed his interest in oriental languages.

The first years he worked as a secretary for Nicolaas Ghisbrechti or Ghysbrechtsz, a jeweller originally from the Southern Netherlands who had been involved in the Capitulations accorded to the Dutch Republic in 1612.

Warner acquired his manuscripts and books through the lively antiquarian booktrade in Istanbul, receiving help and advice from Arabs originally from Aleppo such as Muhammad al-‘Urdi al-Halabi (c. 1602-1660), whose faltering career probably forced him to offer his services to Warner, and the Aleppo-born Sâlih Efendi, known as Ibn Sallum, a physician-in-ordinary to Sultan Mehmed IV who died in 1669.

The Hebrew manuscripts originate mainly from the Karaites, a non-rabbinical Jewish sect which attracted a great deal of interest among contemporary Protestant scholars from Europe.

Highlights include the unique manuscript of Ibn Hazm’s Tawq al-hamama (طوق الحمامة), ‘the Ring of the Dove’, a treatise on love and friendship (Or.

Pétrof in 1914 and many times since, and the oldest extant illustrated Arabic manuscript on a scientific subject, the Kitab al-hasha’ish (كتاب الحشائش), a translation of De Materia Medica by Dioscorides Pedanius.

Their work has not been preserved in the original form, but it was subsequently used by the German student N. Boots or Bootz, whose description of the Warner Legacy takes up a large part of the 1674 catalogue of the Leiden University Library (Spanheim 1674, pp. 316ff).

In 1729 the title of Interpres Legati Warneriani was created by the governors of Leiden University to ensure the continuity of the collection by conservation, cataloguing and the production of scholarly editions.