The cheapest way to get from Barcelona-El Prat Airport (BCN) to the city center in 2026 is by taking the TMB City Bus Line 46 or the NitBus (night bus). A single ticket for these buses costs approximately €2.55, but if you use a multi-trip card like the T-casual, the cost per journey drops significantly. The Line 46 bus operates during the day from both terminals and terminates at Plaça d'Espanya. For those arriving at night, the N17 (Terminal 1) or N16 (Terminal 2) buses offer the same low fare to Plaça de Catalunya. Another very affordable and popular option is the R2 North (R2 Nord) train, which costs around €4.60 for a single ticket and reaches central stations like Passeig de Gràcia in 27 minutes. While the Aerobus shuttle is faster and more frequent, it is more expensive at €7.00. For the ultimate budget-saving "pro" move, purchasing a "Hola Barcelona" travel card allows for unlimited rides on all these public transport options for a set number of days, making your airport transfer virtually "free" within your pre-paid transit budget.