| Honorific-Prefix: | His Excellency |
| Guy Marie Alexandre Thomazeau | |
| Archbishop Of: | Archbishop Emeritus of Montpellier Apostolic Administrator of Nice |
| Enthroned: | 16 December 2002 |
| Ended: | 3 June 2011 |
| Predecessor: | Jean-Pierre Ricard as Bishop of Montpellier |
| Successor: | Pierre-Marie Joseph Carré |
| Ordination: | 18 December 1965 |
| Consecration: | 8 January 1989 |
| Other Post: | Apostolic Administrator of Nice |
| Birth Date: | 5 December 1937 |
| Birth Place: | Neuilly-sur-Seine, France |
| Nationality: | French |
| Religion: | Roman Catholic |
Guy Marie Alexandre Thomazeau (born 5 December 1937) was the Archbishop of Montpellier from 2002 to 2011. He was earlier Bishop of Beauvais, Bishop of Noyon, Bishop of Senlis, and auxiliary bishop of Meaux. Coming from a prominent business family, he served as 'vicaire' at Notre-Dame de Passy and subsequently as 'curé' of St. Pierre de Chaillot in the 16th arrondissement of Paris. He resigned his post of archbishop on 3 June 2011.