| Competition: | Segunda División B |
| Season: | 2002–03 |
| Promoted: | Algeciras Málaga B Ciudad de Murcia Cádiz |
| Relegated: | Marino de Luanco Lugo Real Ávila Ribadesella Gernika Noja Peralta Binéfar Gavà Reus L'Hospitalet Orihuela Díter Zafra Moralo Torredonjimeno Motril Langreo |
| League Topscorer: | Kiko Lacasa (22 goals) |
| Best Goalkeeper: | Javier Oliva (0.43 goals) |
| Biggest Home Win: | Barakaldo 6–0 Binéfar (22 September 2002) Mataró 6–0 Mallorca B (15 December 2002) |
| Biggest Away Win: | Binéfar 0–6 Racing de Santander B (16 March 2003) |
| Highest Scoring: | Peralta 3–7 Zaragoza B (6 April 2003) |
| Prevseason: | 2001–02 |
| Nextseason: | 2003–04 |
The 2002–03 Segunda División B season of began in August 2002 and ended in May 2003.
----Relegated from Segunda División:
----Promoted from Tercera División:
----Relegated:
----Administrative relegation:
----Occupied the vacant spots by administrative relegations:
Teams from Asturias, Canary Islands, Castile and León, Community of Madrid and Galicia.
| Goalscorers | Goals | Team |
|---|---|---|
 Jonathan Sesma | 20 | Universidad Las Palmas |
| Javi Rodríguez | 20 | Pontevedra |
| Nacho Franco | 18 | Lanzarote |
| Luis García | 17 | Real Madrid B |
| José María Simón | 16 | Corralejo |
Teams from Aragon, Basque Country, Cantabria, Castilla–La Mancha, La Rioja and Navarre
| Team | Founded | Home city | Stadium | |
|---|---|---|---|---|
| Alavés B | 1960 | Vitoria, Basque Country | José Luis Compañón | |
| Amurrio | 1949 | Amurrio, Basque Country | Basarte | |
| Athletic Bilbao B | 1964 | Bilbao, Basque Country | Lezama | |
| Aurrerá Vitoria | 1935 | Vitoria, Basque Country | Olanrabe | |
| Barakaldo | 1917 | Barakaldo, Basque Country | Ciudad Deportiva de San Vicente | |
| Binéfar | 1922 | Binéfar, Aragon | Los Olmos | |
| Calahorra | 1946 | Calahorra, La Rioja | La Planilla | |
| Conquense | 1946 | Cuenca, Castilla–La Mancha | La Fuensanta | |
| Gernika | 1922 | Gernika, Basque Country | Urbieta | |
| Gimnástica Torrelavega | 1907 | Torrelavega, Cantabria | El Malecón | |
| Logroñés | 1940 | Logroño, La Rioja | Las Gaunas | |
| Noja | 1963 | Noja, Cantabria | La Caseta | |
| Osasuna B | 1962 | Aranguren, Navarre | Tajonar | |
| Peña Sport | 1925 | Tafalla, Navarre | San Francisco | |
| Peralta | 1927 | Peralta, Navarre | Las Luchas | |
| Racing Santander B | 1926 | Santander, Cantabria | La Albericia | |
| Real Unión | 1915 | Irún, Basque Country | Stadium Gal | |
| Talavera | 1948 | Talavera de la Reina, Castilla–La Mancha | El Prado | |
| Toledo | 1928 | Toledo, Castilla–La Mancha | Salto del Caballo | |
| Zaragoza B | 1958 | Zaragoza, Aragon | Ciudad Deportiva del Real Zaragoza |
| Goalscorers | Goals | Team |
|---|---|---|
| Kiko Lacasa | 22 | Alavés B |
| Paulino Martínez | 18 | Logroñés |
| Iván Estecha | 17 | Talavera |
| Nacho Rodríguez | 15 | Racing B |
| Alberto Alejandro | 14 | Barakaldo |
Teams from Balearic Islands, Castile and León, Catalonia and Valencian Community
| Goalscorers | Goals | Team |
|---|---|---|
| Sergio García | 19 | Barcelona B |
| Jorge Barbarín | 16 | Burgos |
| Javier Morante | 16 | Alicante |
| Raúl Caballero | 15 | Gramenet |
| Nano García del Pozo | 15 | Lleida |
Teams from Andalusia, Ceuta, Extremadura, Melilla and Region of Murcia
| Goalscorers | Goals | Team |
|---|---|---|
| Alexandre Geijo | 16 | Málaga B |
| Francisco Nogueira | 16 | Ciudad Murcia |
| Julio Cobos | 14 | Cacereño |
| Nacho Garrido | 14 | Cacereño |
| Tati Maldonado | 13 | Betis B |