Short answer: Yes — but only in limited/trial form across parts of the island as of Sept 2, 2025.

Details:

• Major Sri Lankan operators (Dialog Axiata and SLT‑Mobitel) have active 5G trial / pre‑commercial networks and have been running 5G (including 5G SA/5G‑Advanced) demos and customer trials in cities such as Colombo and other key locations. (mydialog.dialog.lk, dailynews.lk)
• Measurement reports show Sri Lankan users are already seeing 5G experience and significant 5G speeds on those networks. (opensignal.com)
• However, a full, island‑wide commercial 5G rollout based on formally assigned spectrum was still pending TRCSL’s spectrum assignment/auction process (authorities and news outlets reported an auction was imminent with a wider rollout planned later in 2025). (datacenterdynamics.com, dailymirror.lk)

If you want to know whether 5G is available at a specific location in Sri Lanka, checking the local operator’s 5G coverage map (Dialog, Mobitel, Hutch) or looking for a 5G signal on a 5G‑capable phone/SIM in that area is the quickest way.