Mill Valley Way is a 21st century development. Like many roads in this area, it gets its name from the fact that Ligoniel was a mill village. There was a beetling mill nearby at the confluence of the Ligoniel River and the Forth River. Later, in 1857-59 a flax spinning mill was built by John Emerson a little further north and upstream (which became the Ballysillan Flax Spinning Mill), and there was also a weaving factory.
The name Mill Valley Way, off Mill Valley Place, was put forward by Lagan Homes has been proposed as a continuation theme from the existing streets in the surrounding area. Health and Environmental Services Committee, 4th June 2014.
Dual language street sign (English and Irish) approved in February 2024.