Sigfrid Vilhelm Arnell, also sometimes Sigfrid Wilhelm Arnell (1895 in Gävle – 1970), was a Swedish medical practitioner and hepaticologist. He was the son of bryologist Hampus Wilhelm Arnell (1848–1932). After finishing his education in Uppsala and Stockholm, he worked at the hospital in Gävle, where he was director of its roentgenological department from 1927 up until retirement in 1960. Following retirement he resided in Bromma, and in 1963, relocated to Uppsala. In his later years, he suffered from Parkinson's disease and was plagued by failing eyesight.