| Alfonso Martín | |
| Full Name: | Alfonso Martín Castillo |
| Birth Date: | 10 June 1994 |
| Birth Place: | Jerez de la Frontera, Spain |
| Height: | 1.82 m |
| Position: | Midfielder |
| Youthclubs1: | Xerez |
| Years1: | 2013 |
| Caps1: | 1 |
| Goals1: | 0 |
| Years2: | 2013 |
| Caps2: | 3 |
| Goals2: | 0 |
| Years3: | 2013–2014 |
| Caps3: | 7 |
| Goals3: | 0 |
| Years4: | 2014 |
| Caps4: | 12 |
| Goals4: | 0 |
| Years5: | 2014–2016 |
| Caps5: | 70 |
| Goals5: | 2 |
| Years6: | 2016–2017 |
| Caps6: | 30 |
| Goals6: | 2 |
| Years7: | 2017–2018 |
| Caps7: | 27 |
| Goals7: | 0 |
| Years8: | 2018–2019 |
| Caps8: | 35 |
| Goals8: | 3 |
| Years9: | 2019–2021 |
| Caps9: | 0 |
| Goals9: | 0 |
| Years10: | 2019–2020 |
| Clubs10: | → Cultural Leonesa (loan) |
| Caps10: | 23 |
| Goals10: | 0 |
| Years11: | 2020–2021 |
| Clubs11: | → Atlético Baleares (loan) |
| Caps11: | 12 |
| Goals11: | 0 |
| Years12: | 2021–2023 |
| Caps12: | 37 |
| Goals12: | 0 |
| Years13: | 2023–2024 |
| Caps13: | 21 |
| Goals13: | 0 |
| Club-Update: | 11 April 2024 |
Alfonso Martín Castillo (born 10 June 1994), sometimes known as Alfonsito, is a Spanish footballer who plays as a midfielder.
Born in Jerez de la Frontera, Cádiz, Martín graduated from Xerez CD's youth system, and made his senior debut with the reserves on 7 January 2013, against GE Bazán CF.[1]
On 3 May 2013, Martín made his debut for the first team, in a 1–3 home defeat against Córdoba CF in the Segunda División championship.[2] In August he moved to the latter, being assigned to the B-side in Segunda División B.[3]
In January 2014, after being rarely used, Martín moved to Écija Balompié also in the third division. On 21 August, he joined Tercera División side CD Guadalcacín.[4]
On 11 July 2016, Martín returned to the third level after agreeing to a contract with Real Balompédica Linense.[5] Roughly one year later he signed for another reserve team, CD Vitoria in the same division.[6]
On 2 August 2018, Martín signed for UD Melilla still in the third tier.[7] The following 12 July, he agreed to a three-year contract with AD Alcorcón in the second division, but was immediately loaned to Cultural y Deportiva Leonesa for one year.[8]
On 25 August 2020, Martín was loaned to fellow third division side CD Atlético Baleares for the 2020–21 campaign.[9]