Ryan Seth James Miller (born 1974 in Albuquerque, New Mexico is the younger brother of Rand and Robyn Miller, the co-founders of Cyan (now Cyan Worlds). Ryan eventually joined the Cyan team in 1995.

As a child Ryan moved about a lot and lived in many places such as Honolulu, Philadelphia, Texas, Haiti and Seattle. Ryan went to the University of Washington however in 1993 he took a quarter off to write the first draft of the Book of Atrus. He never completed university as he fell in love and moved back to Spokane, Washington.

In his role at Cyan, Ryan has done many different things. In 1991, between his junior and senior years of high school, he did various jobs, one of which was writing the journals of Atrus featured in the best-selling computer game Myst. Since being hired, Ryan has worked on all of the Myst games and novels.