There are three to five daily flights between Con Son and HCMC jointly operated by Vasco and Vietnam Airlines (www.vietnamairlines.com). Tickets cost US$60 to US$80 one way. Con Son is also connected to Can Tho in the Mekong Delta via Vasco/Vietnam Airlines; there are four weekly flights, if you book well ahead they can be as low as US$28 one-way.
The tiny airport is about 15km from the town centre. All the big hotels on the island provide free transport both to and from the airport. It's nearly always possible to show up and grab a seat on one of the hotel shuttle vans that meet the planes; drivers charge 50,000d and will usually drop you off at your hotel or in the town centre.