Does a Swedish citizen need a return ticket to get a visa to Tanzania?

No you don't, I'm Swedish and I have a lot of Swedish friends here and none of us has a ticket back to Sweden :)
I'm not Swedish, but I have flown into Tanzania 20+ times in the past ten years (Zanzibar and mainland), alsways getting a visa on arrival, and nobody has ever asked to see a return ticket. All you do is state the number of days you are planning to stay in the country.
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