Yes, most modern and long-distance Polish trains (PKP Intercity) are equipped with free Wi-Fi, though the quality varies. On the high-speed Pendolino (EIP) trains, the Wi-Fi is generally reliable and fast enough for emails and light browsing. On the standard InterCity (IC) and TLK trains, Wi-Fi is becoming a standard feature on newer or refurbished rolling stock, typically indicated by a Wi-Fi symbol on the exterior of the carriage. To connect, you usually just need to accept the terms of service on a landing page. However, be aware that the system relies on cellular towers; when the train passes through the thick forests or mountainous regions of southern Poland, the signal will frequently drop or slow to a crawl. For regional trains (Koleje Mazowieckie, Polregio), Wi-Fi is much less common and usually reserved for newer commuter routes around major hubs like Warsaw or Kraków. If you have a critical meeting, it is always safer to have a local SIM card with a data plan as a backup.