World Metrology Day celebrates the signature by representatives of seventeen nations of The Metre Convention on 20 May 1875. The Convention set the framework for global collaboration in the science of measurement and in its industrial, commercial and societal application. The original aim of the Metre Convention - the worldwide uniformity of measurement - remains as important today as it was in 1875.

The World Metrology Day project is currently realized jointly by the BIPM and the OIML together with PTB International Technical Cooperation.