Tobias Michael Carel Asser (April 28, 1838, Amsterdam – July 29, 1913, The Hague) was a Dutch lawyer and legal scholar of Jewish background, cowinner (with Alfred Fried) of the Nobel Prize for Peace in 1911 for his role in the formation of the Permanent Court of Arbitration at the first Hague peace conference (1899). In 1902, he sat on the first arbitration panel to hear an international controversy brought by two states under auspice of the Permanent Court of Arbitration, the Pious Fund of the Californias Case. He also advocated for the creation of an international academy of law, which led to founding of the Revue de Droit International et de Législation Comparée with John Westlake and Gustave Rolin-Jaequemyns, the Institut de Droit International and the creation of the Hague Academy of International Law.

He was son of Carel Daniel Asser (1813-85), and grandson of Carel Asser (1780-1836). He studied law at the University of Amsterdam and Leiden University and was law professor at the University of Amsterdam.

Asser (d. 908/909) was a Welsh monk from St David's, Dyfed, who became Bishop of Sherborne in the 890s. About 885 he was asked by Alfred the Great to leave St David's and join the circle of learned men whom Alfred was recruiting for his court. After spending a year at Caerwent because of illness, Asser accepted.

In 893 Asser wrote a biography of Alfred, called the Life of King Alfred. The manuscript survived to modern times in only one copy, which was part of the Cotton library. That copy was destroyed in a fire in 1731, but transcriptions that had been made earlier, together with material from Asser's work which was included by other early writers, have enabled the work to be reconstructed. The biography is the main source of information about Alfred's life and provides far more information about Alfred than is known about any other early English ruler. Asser assisted Alfred in his translation of Gregory the Great's Pastoral Care, and possibly with other works.

Asser is sometimes cited as a source for the legend about Alfred's having founded the University of Oxford, which is now known to be false. A short passage making this claim was interpolated by William Camden into his 1603 edition of Asser's Life. Doubts have also been raised periodically about whether the entire Life is a forgery, written by a slightly later writer, but it is now almost universally accepted as genuine.