Yes—but not officially. Thanks to the PS4’s native PS2 emulator (PS2 Classics), the modding community has created custom PKG files that allow you to run this legendary racing sim directly from your PS4 dashboard.
October 2023 Subject: PS2 Classics on PS4 / Emulation Preservation Platform: PlayStation 4 (PS4) gran turismo 4 ps4 pkg best
(Best Overall): This is a comprehensive fan-made expansion built on the NTSC online beta. Yes—but not officially