Amatsyaśī (Amatsyasi) is one of the sons of Maharṣi (Maharshi; Great Sage) Viśvāmitra (Viswamitra).

Mahābhārata (Kinjawadekar)(13.4.59)
Mahābhārata Vols. 1-43 (Siddhāntabāgīśa)(13.3.78)