Yes. Tinnitus on its own is not a contraindication to flying. Cabin pressure changes during ascent and descent can briefly affect the middle ear, and many people find their tinnitus is louder for a few hours after a flight, but the effect is temporary and not damaging.
A few practical tips. Use simple equalising techniques on descent — swallowing, yawning, gentle Valsalva (pinch your nose, gently push air against closed lips). Stay well hydrated; the cabin air is dry and dehydration tends to nudge tinnitus up. If you are prone to ear pain on descent, EarPlanes or similar pressure-regulating earplugs are inexpensive and worth trying. Avoid flying with an active cold, sinus infection or ear infection if you can; the eustachian tube cannot equalise properly and you can give yourself an unpleasant barotrauma.
If you have hearing aids, take them, but most people switch them off during the flight because of cabin noise.
The in-flight engine noise itself sits around 80–85 dB and is below the threshold of clear damage for a few hours, but if you find it bothersome, foam plugs or noise-cancelling headphones are reasonable.