The woman's body was discovered on Tuesday evening in a forest area in Hultsfred municipality.
The circumstances of her death were initially unclear, but after forensic teams had examined the site, police launched a murder investigation.
A man was taken into custody for questioning shortly after midnight.
“We have a man who has been arrested on suspicion of murder,” police spokesperson Jimmy Modin told the TT newswire early on Wednesday morning.
He said the woman had not yet been identified.
“We have not been able to speak to relatives,” Modin told the Aftonbladet tabloid.
The suspected murder casts a dark shadow over a usually calm and quiet rural area.
Her body was found in Silverdalen, near the village of Lönneberga in Sweden's picturesque Småland region, an area made famous in novels by famous Swedish children's author Astrid Lindgren.
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Lindgren's books about the young boy Emil and his family are set at a farm in Lönneberga.