What is the largest island of the Mariana Islands?

Answer

Guam -- 542 km

The previous answer, Honshu, is the largest Island of Japan, but it is not one of the Mariana Islands. Other islands in the Marianas are:

Agrihan - 47 km²

Aguijan - 7 km²

Alamagan - 11 km²

Amatahan - 32 km²

Asuncion - 7.4 km²

Farallon de Medinilla - 0.9 km²

Farallon de Pajaros - 2 km²

Guguan - 4 km²

Maug Islands (actually, 3 islets) - total area is < 2 km²

Pagan - 48 km²

Rota - 85 km²

Saipan - 115 km²

Sarigan - 5 km²

Tinian - 101 km²

Some websites will cite Saipan as being the largest of these islands. Saipan is the largest of the Northern Marianas (which is a Commonwealth), but not of the total chain.