Network Rail Limited is the owner (via its subsidiary Network Rail Infrastructure Limited, which was known as Railtrack plc before 2002) and infrastructure manager of most of the railway network in Great Britain.

As of 2026, the ownership of the UK's railway system has undergone a massive transformation under the Great British Railways (GBR) initiative. Following the Passenger Railway Services (Public Ownership) Act, the vast majority of train operating companies have returned to public ownership. By February 2026, over half of all rail services—including major lines like London Northwestern, West Midlands Railway, LNER, and Northern—are run by the government's Department for Transport (DfT). The goal is to move away from the fragmented "franchising" model of the past and into a unified, publicly-owned system where GBR manages both the tracks (formerly Network Rail) and the trains. While some private contracts still exist (like Chiltern and GWR), the government expects the full transition to public ownership to be completed by late 2027. This shift is designed to prioritize passenger needs, freeze fares, and create a more reliable, "joined-up" network where revenue is reinvested directly back into the service rather than being distributed as dividends to private shareholders or foreign state-owned companies.