 Ithan Creek rises in a small valley just south of U.S. Route 30 in the community of Wayne, Pennsylvania. It flows west for several tenths of a mile before receiving its first tributary, Browns Run, from the right and turning south. The creek passes under Pennsylvania Route 320 and receives two small unnamed tributaries from the left. It flows alongside Interstate 476 and crosses it once. After a short while, it receives Kirks Run from the right near the community of Rosemont, Pennsylvania. It flows alongside the interstate for several tenths of a mile before passing under it again. Shortly thereafter, Ithan Creek enters Haverford Township, Pennsylvania and receives its largest tributary, Meadowbrook Run. It passes under Darby Road and meets its confluence with Darby Creek.
