Sir Anthony Siaguru KBE (4 November 1946 – 16 April 2004) was a Papua New Guinean civil servant, lawyer, international diplomat, politician, sportsman and anti-corruption campaigner.

Siaguru played a major role in shaping PNG's foreign policy of "Friends to All, Enemies to None" and in persuading the prime minister, Michael Somare, to give diplomatic recognition to China.

Among his roles was to support the transition process from apartheid in South Africa, leading up to the 1994 election when the African National Congress, led by Nelson Mandela achieved a majority.

For the Post-Courier, he wrote a weekly column called In House, in which he condemned corruption in PNG, and made proposals for constitutional reform, in part to address the numerous political parties in the country.

He launched the Integrity Pact at the time of the 1997 national elections, requiring politicians to sign a Charter committing themselves to transparent governance.

He was survived by his wife, Wilhelmina (Mina), who served for many years as Chairperson of PNG's Commission for Higher Education, whom he married in 1972, and three sons.