A Machine Readable Travel Document (MRTD) is an international travel document (e.g. a passport or visa) containing eye-and machine-readable data.

Each type of MRTD contains, in a standard format, the holder's identification details, including a photograph or digital image, with mandatory identity elements reflected in a two-line machine readable zone (MRZ) printed in Optical Character Recognition-B (OCR-B) style. Standardization of elements in the travel document allows all participating countries inter-operability.

This "global inter-operability" of MRTDs facilitates inspection of international travellers at borders and generally enhances security.

MRTDs currently in existence include Machine Readable Passports (MRP), Machine Readable Visas (MRVs) and Machine Readable Official Travel Documents (TDs).

MRTDs are developed with the assistance of ICAO's Technical Advisory Group on Machine Readable Travel Documents (TAG/MRTD) with technical and engineering input from ISO Working Group 3 (JTC1/SC17/WG3). These specifications are published in ICAO Doc 9303 and endorsed by ISO as ISO/IEC 7501. The TAG also draft guidance materials to assist States to implement the specifications, Technical Reports and Information Papers, to guide States and private industry on present and future aspects of its work.

ICAO's mandate to develop MRTDs is provided by Articles 22, 23 and 37 of the Chicago Convention which oblige Contracting States to develop and adopt international standards for customs, immigration and other procedures to facilitate the border-crossing processes involved in international air transport.

ICAO took the initiative in order to address the clearance of increased passengers volumes that came with the emergence of wide body aircraft, and published the first edition of Doc 9303 in 1980.