Darlington was born on May 3, 1968, in Sidcup, Kent. He went to Oxted County Senior School in Oxted, Surrey, England. He joined Kula Shaker as an organ player in 1994. He departed in 1999.
He originally joined Oasis in 2004 as a live keyboardist. He played on the subsequent tours, up until the very last tour in the summer of 2009. During the tours of the last album, Noel Gallagher would introduce and thank both Darlington and new drummer Chris Sharrock. He sometimes did this with Zak Starkey on the previous album's tours, as they were both essentially touring members. During these introductions and thank yous, Gallagher would often refer to him as "The Shroud", or more popularly, "Jesus Christ", a reference to Darlington's hair and facial hair arrangement. This led to chants of "Jesus, Jesus, Jesus ..." at the later concerts. In the Lord Don't Slow Me Down film's commentary, Gallagher refers to him as "Gandalf".