You can travel Sri Lanka for three weeks out of a carry-on. Laundry is cheap and fast everywhere, so pack for four days, not for the trip.
Non-negotiable
- One long-sleeve shirt and long trousers or a sarong for temples — shoulders and knees covered, shoes off
- A warm layer for the hill country; Nuwara Eliya drops to 8°C at night and hotels rarely have heating
- Reef-safe sunscreen and a rash vest
- Slip-on shoes, because you will take them off many times a day
Worth the space
A dry bag for boat trips, a head torch for pre-dawn hikes, electrolyte sachets, and a plug adapter — Sri Lanka uses Type D and G sockets.
Leave it home
Heavy hiking boots unless you are trekking the Knuckles, a hair dryer, and anything you would be upset to lose to humidity.
Leech socks
If you are walking in the Knuckles or Sinharaja in the wet season, rent a pair locally. You will want them.