Arwon (foaled 8 September 1973, died 25 May 2007) was a New Zealand-bred thoroughbred racehorse by Aritzo from Fair Flash who won the 1978 Melbourne Cup.
In New Zealand, he was known and raced as Flash Guy. Arwon won the 1978 Melbourne Cup, beating Dandeleith and Karu by a half neck. He ran in two more Melbourne Cups, finishing ninth in 1980 to Beldale Ball and fifth in 1981 to Just A Dash.
The name 'Arwon' was made from reversing the word Nowra, a town in New South Wales where one of the syndicate that owned him lived. Arwon started in 67 races, won 16 starts, was second 13 times and finished third five times.