Police said the victim, a 38-year-old man, was one of two riders in the northbound right-hand lane on Sunrise Valley near Coppermine Road about 8 p.m.
Neither rider was wearing reflective clothing, nor did they have any lights on their bicycles, said police.
A 2014 Chevrolet Suburban (SUV), driven by a 29-year-old Fairfax man, also traveling north on Sunrise Valley Drive, approached the bicycles from behind and struck one of the riders.
The rider, whose name has not been released by police because next of kin has not been notified, was taken to Reston Hospital Center, where he was pronounced dead later on Monday.
The driver of the SUV remained on the scene. Speed and alcohol do not appear to be factors in this crash, police said.
Police are still investigating the crash. Anyone with information regarding this crash is asked to contact Crime Solvers electronically by visiting www.fairfaxcrimesolvers.org or text-a-tip by texting “TIP187” plus your message to CRIMES(274637)** or by calling 1-866-411-TIPS(8477), or call Fairfax County Police at703-691-2131 .