The convict did not attend the appeal hearing at the court in the Balinese capital Denpasar.
Sara Connor, 46, was handed a four-year jail term in March after being found guilty along with her British DJ boyfriend of killing officer Wayan Sudarsa, who was beaten to death on a popular beach on the island.
The Briton, 34-year-old David Taylor, was jailed for six years.
Traffic policeman Sudarsa's blood-soaked body was found in August covered with dozens of wounds on his neck, chest and head.
Taylor, whose stage name is DJ Nutzo, admitted getting into a fight with Sudarsa on the beach after accusing the officer of stealing Connor's handbag. Mother of two Connor had maintained her innocence but judges found her guilty, ruling she had held the victim down during the fight.
Prosecutors appealed the four-year sentence for Connor, which was lower than the eight years they had recommended to the judges, arguing it would not have enough of a deterrent effect.
Bali High Court Monday increased the term by one year. The judges said the reasons were that her actions could impact the tourism industry and she had left the victim to die when he was lying face down on the beach.
"The defendant has damaged the image of Indonesian tourism, especially tourism on Bali," said judge Sutoyo, who like many Indonesians goes by one name.
Connor did not attend the appeal hearing at the court in the Balinese capital Denpasar.
Bali, a pocket of Hinduism in Muslim-majority Indonesia, is a popular tourist destination known for its tropical climate and palm-fringed beaches.
Minor crime is common but murders are rare.