Arnold David Lanni (born 4 May 1956) is a Canadian record producer and former member of Frozen Ghost and Sheriff. He wrote Sheriff's most successful song, "When I'm with You."
Sheriff members Lanni and Wolf Hassel formed Frozen Ghost, which existed 1985 to 1993. Lanni was a guitarist, keyboardist and vocalist for this project.
Lanni has produced Canadian rock groups such as Finger Eleven, Simple Plan, the first four Our Lady Peace albums (including the diamond-certified Clumsy), Hello Operator, Thousand Foot Krutch, Echo Jet, The Waking Eyes and Rev. He has also produced American groups The Gufs and King's X (Ear Candy).