| Julio Alonso | |
| Fullname: | Julio Alonso Sosa |
| Birth Date: | 14 December 1998 |
| Birth Place: | Terrassa, Spain |
| Height: | 1.70 m |
| Position: | Left back |
| Currentclub: | Mirandés |
| Youthclubs1: | Jàbac Terrassa |
| Youthyears2: | 2014–2016 |
| Youthclubs2: | Damm |
| Youthyears3: | 2016–2017 |
| Youthclubs3: | Betis |
| Years1: | 2017–2021 |
| Clubs1: | Betis B |
| Caps1: | 100 |
| Goals1: | 2 |
| Years2: | 2021–2024 |
| Clubs2: | Albacete |
| Caps2: | 102 |
| Goals2: | 1 |
| Years3: | 2024– |
| Clubs3: | Mirandés |
| Caps3: | 0 |
| Goals3: | 0 |
| Club-Update: | 29 May 2024 |
Julio Alonso Sosa (born 14 December 1998) is a Spanish professional footballer who plays as a left back for CD Mirandés.
Born in Terrassa, Barcelona, Catalonia, Alonso joined Real Betis' youth setup in 2016, after representing CF Damm and UFB Jàbac Terrassa.[1] He made his senior debut with the reserves on 27 August 2017, coming on as a second-half substitute for Redru in a 4–1 Segunda División B away loss against Real Balompédica Linense.
Alonso immediately became a regular starter for the B-team, suffering relegation to Tercera División in his first season but achieving promotion back in his third; he scored his first senior goal for the side on 29 September 2019, netting the B's third in a 4–1 away routing of Córdoba CF B. On 17 June 2021, he signed a two-year contract with Albacete Balompié, freshly relegated to Primera División RFEF.[2]
A first-choice for Alba as the club returned to Segunda División at first attempt, Alonso made his professional debut on 15 August 2022, starting in a 2–1 away win against CD Lugo.[3] Regularly used, he left the club on 30 June 2024 as his contract expired.[4]
On 2 August 2024, Alonso agreed to a one-year deal with CD Mirandés in the second division.[5]