|Date of birth||29 March 1931|
|Place of birth||Florence, Italy|
|Date of death||3 December 2020 (aged 89)|
|Place of death||Florence, Italy|
|Height||1.68 m (5 ft 6 in)|
|* Senior club appearances and goals counted for the domestic league only|
In 2014, he was inducted into ACF Fiorentina Hall of Fame.
After one season at Ascoli, he was bought by Bari for the 1953–54 IV Serie, where he spent most of his career, becoming the captain and reaching Serie A in 1958. At Bari, he made a total of 313 appearances and scored 25 goals (of which 90 appearances and 7 goals in Serie A), becoming the third player with most appearances in the club's history.
In 1970, Mazzoni was appointed as assistant coach of Fiorentina. At the end of the 1974–75 season, he replaced Nereo Rocco, who had quit his role of first team coach, leading the club to the victory of the 1974–75 Coppa Italia. He also led Siena during the 1978–79 Serie C2.
- "Mario Mazzoni". Enciclopediadelcalcio.it. Archived from the original on 4 March 2016. Retrieved 4 March 2016.
- Papini, Roberto Davide (17 May 2019). "Fiorentina in lutto: è morto Mazzoni, maestro dei giovani viola. Vinse una Coppa Italia". La Nazione (in Italian). Retrieved 11 April 2021.
- Prizio, Stefano; Signoria, Leonardo (2016). La Fiorentina dalla A alla Z. Newton Compton Editori. ISBN 8854195448.
- "Carriera storica di Mario Mazzoni, goal e presenze". CarriereCalciatori.it (in Italian). Archived from the original on 8 October 2016. Retrieved 11 April 2021.
- "La Storia 2". Robur1904.it (in Italian). Retrieved 12 April 2021.
- "IV Hall of Fame Viola: Toldo, Chiarugi e non solo entrano nella galleria degli onori". Viola News (in Italian). 8 December 2015. Archived from the original on 22 March 2019. Retrieved 17 February 2020.
- "Il "mitico" Mario Mazzoni compie 85 anni: gli auguri delle Glorie Viola". Viola News (in Italian). 29 March 2016. Retrieved 12 April 2021.