Spanish Railways (RENFE) operates a train from Frómista to Madrid Airport (MAD) twice a week. Tickets cost $30 - $45 and the journey takes 2 h 21 min. Madrid Cercanías (RENFE) also services this route every 30 minutes.
From Fromista train to Chamartín then train to Aeropuerto T4. 2 h 52 min £33. From Fromista bus to Burgos then night bus to Madrid - Barajas Airport T4. 5 h £35. From Frómista drive to Madrid Airport (MAD). 2 h 53 min £28.