Sigtrygg II Silkbeard Olafsson (also Sihtric, Sitric and Sitrick in Irish texts; or Sigtryg and Sigtryggr in Scandinavian texts) was a Hiberno-Norse king of Dublin (possibly AD 989–994; restored or began 995–1000; restored 1000 and abdicated 1036) of the Uí Ímair dynasty. He was caught up in the abortive Leinster revolt of 999–1000, after which he was forced to submit to the King of Munster, Brian Boru.