Diana Žiliūtė ([dʲɪjɛˈnɐ ʑɪˈlʲuːtʲeː]; born 28 May 1976 in Rietavas) is a Lithuanian racing cyclist who dominated women's road racing in the late 1990s.
She made her debut in the pro cycling ranks in the mid-1990s after winning the 1994 World Junior Road Race Championship. She rose to the top of women's cycling in 1998 when she won two World Road Cup races, the overall World Road Cup title, and capped the season by winning the World Road Race Championships and leading the UCI Women's Road World Rankings.
The following year (1999), she further demonstrated her all around prowess by winning the Grande Boucle, one of the hardest stage races in women's cycle racing history. This was followed in 2000 by a bronze medal at the Summer Olympics.
For her achievements, Žiliūtė was awarded the Order of Gediminas, a Lithuanian state honor.