In the summer months, both Alaska Airlines and Delta Airlines fly to Sitka. It is about a 2.5 hour flight from Seattle. Typically, we suggest booking through Alaska Airlines because their pilots are more accustom to flying in weather conditions that may cancel a flight on another airline. They also have generous free bag perks (which is nice for shipping fix boxes) if you book with an Alaska Airlines credit card. However, if Delta has a better hub airport for you, its also a great option for getting to Sitka.
Although less common, you can also get to Sitka via the Alaska Marine Highway (ferry). This is best for guests looking for a roadtrip adventure that ends in fishing. You can drive through British Columbia (passport needed) to the quaint town of Haines, Alaska for a 9.5 hour ferry to Sitka. At this time, ferry tickets can only be booked 3 months in advance and travel 1 day a week.