Most intercity buses you might need in Odesa leave from the three poorly organised bus stations located within a few hundred metres of each other in the area between the railway station and Privoz Market.
Gunsel buses for Kiev (400uah, six to seven hours, five daily) depart from the new slick, but not particularly user-friendly, Starosinna bus station. Across the road, Privokzalna bus station handles frequent buses for Bilhorod-Dnistrovsky (70uah, 2½ hours) via Zatoka and Shabo.
Closer to the market, the slightly chaotic Privoz bus station is primarily useful for Vylkove (190uah, three to four hours, four daily). Here you can also catch the daily bus to Reni on the Moldovan/Romanian border (210uah, seven hours, three daily) and Chișinău in Moldova (290uah, five to seven hours, many daily). Note that many of the latter pass through Tiraspol (105uah, three hours) in the breakaway territory of Transnistria. If you want to avoid that, ask for a bus going via Palanka.
Buses for Chornomorsk depart from both Privoz and Starosinna bus stations (26uah, one hour, every 15 minutes).
Note that small bus operators migrate between all three central stations, so if there is no convenient bus to your destination at one of them, check at the others.
Most international and long-haul domestic buses leave from the long-distance bus station, 3km west of the train station. Apart from Kyiv, there are services to most large cities in Ukraine, including Kherson (130uah to 170uah, three to four hours, hourly), Lviv (700uah to 900 uah, 15 hours, three daily), Dnipro (440uah, 9½ hours, five daily) and Chernivtsi (530uah, 13 hours, two daily) via Kamyanets-Podilsky.
There is at least one daily bus to Bucharest in Romania (815 to 1000uah, 12 hours).
A daily Intercity+ train (340uah, seven hours) and a couple of daily overnight trains (platskart/kupe 130/350uah, 9½ to 13 hours) connect Odesa with Kyiv. There are also services to Lviv (platskart/kupe 150/240uah, 12 hours, four daily), Dnipro (platskart/kupe 185/315uah, 11 hours, two daily) and Kharkiv (platskart/kupe 210/350uah, 14½ hours, daily).
International destinations include Chişinău (190uah, five hours, daily), Moscow (platskart/kupe 2360/4000uah, 24 hours, daily) and Minsk (platskart/kupe 1450/2200uah, 22 hours, daily).