Dingeman Adriaan Henry van der Sluijs, better known by his stage name Dick Diamonde, is an Australian former bass guitarist. He was a founding mainstay member of the Easybeats. Diamonde, with the group, was inducted into the ARIA Hall of Fame in 2005.

The Easybeats were an Australian rock band which formed in Sydney in late 1964. They are best known for their 1966 hit single "Friday on My Mind", which is regarded as the first Australian rock song to achieve international success; Rolling Stone described it as "the first international victory for Oz rock". One of the most popular and successful bands in the country, they were one of the few Australian bands of their time to foreground their original material; their first album Easy (1965) was one of the earliest Australian rock albums featuring all original songs.