| Guy III of Spoleto | |
|---|---|
| Emperor of the Romans | |
 Guy depicted as emperor in the 12th-century cartulary of San Clemente | |
| Emperor in Italy | |
| Reign | 891–894 |
| Coronation | 21 February 891, Rome |
| Predecessor | Charles III |
| Successor | Lambert |
| King of Italy | |
| Reign | February 889 – 894 |
| Predecessor | Berengar I |
| Successor | Lambert |
| Died | 12 December 894 Taro River, Italy |
| Burial | |
| Spouse | Ageltrude |
| Issue | Lambert, Arnaldo of Spoletto (Arnaldo de Baião), Bernardo of Spoletto, Guy IV of Spoletto |
| House | Guideschi |
| Father | Guy I |
| Mother | Itta of Benevento |
Guy III of Spoleto (German: Wido, Italian: Guido; died 12 December 894) was the Margrave of Camerino from 880 and then Duke of Spoleto and Camerino from 883. He was crowned King of Italy in 889 and emperor in 891. He died in 894 while fighting for control of the Italian Peninsula.
Guy was married to Ageltrude, daughter of Adelchis of Benevento, who had a son with him named Lambert.