Shepseskare Isi, also spelt Shepseskare, (in Greek known as Sisiris), is a Pharaoh of Egypt during the Fifth dynasty, who is thought to have reigned from around 2455 to 2448 BCE.

His throne name means "Noble is the Soul of Re."

However, he is the most ephemeral ruler of this dynasty and some Egyptologists such as Miroslav Verner have strongly argued that Shepseskare's reign lasted only a few months at the most based upon the evidence of an unfinished fifth dynasty royal pyramid at Abusir, whose base was barely completed before it was abandoned as well as the very small number of objects identifying this king.

The state of the unfinished Abusir pyramid tells us that this king's reign was unexpectedly cut short.

However, both the Turin King List and Manetho state that Shepseskare ruled Egypt for seven years.