|Full name||Gonzalo Pablo Castellani|
|Date of birth||10 August 1987|
|Place of birth||Buenos Aires, Argentina|
|Height||1.79 m (5 ft 10 in)|
|Defensa y Justicia (on loan from Boca Juniors)|
|Ferro Carril Oeste|
|2006–2010||Ferro Carril Oeste||102||(12)|
|2015–2016||→ Lanus (loan)||4||(0)|
|2016–||→ Defensa y Justicia (loan)||0||(0)|
|* Senior club appearances and goals counted for the domestic league only and correct as of 30 December 2015.
Castellani started his professional career with local Ferro Carril Oeste, competing in Primera B Nacional with the Buenos Aires outfit. On 2 January 2010 he moved to Spain and signed for Villarreal CF, being assigned to its B team in Segunda División; he failed to make any appearances for the club during the season, due to the team's excessive number of foreign players.
Castellani made his official debut for Villarreal B on 16 January 2011, starting in a 0–2 away loss against Recreativo de Huelva. On 18 December he first appeared in La Liga with the main squad, replacing Cani in the 64th minute of a 1–2 defeat at CA Osasuna.
- "Gonzalo 'Boni' Castellani, segundo refuerzo amarillo" [Gonzalo 'Boni' Castellani, new amarillo signing] (in Spanish). Diario AS. 2 January 2010. Retrieved 7 July 2012.
- "Castellani: "Nunca pensé que estaría seis meses sin jugar"" [Castellani: "I never thought I would be six months without playing"] (in Spanish). Fútbol Argentino. 27 January 2011. Retrieved 7 July 2012.
- "Recreativo 2-0 Villarreal B" (in Spanish). RFEF. 16 January 2011. Retrieved 7 July 2012.
- "Osasuna close in on Euro spot". ESPN Soccernet. 18 December 2011. Retrieved 7 July 2012.
- Castellani ficha por el Godoy Cruz de Argentina (Castellani signs for Godoy Cruz of Argentina); Marca, 6 July 2012 (in Spanish)
- Gonzalo Castellani, el nuevo refuerzo para el Boca de Carlos Bianchi (Gonzalo Castellani, reinforcement for Carlos Bianchi's Boca); Canchallena, 3 July 2014 (in Spanish)