Svein Ludvigsen, 72, was charged with one count of taking advantage of his position as regional governor, and one count of exploiting the asylum seekers' vulnerable situation, to abuse them sexually.
"The prosecution authorities have charged a former politician with the sexual abuse of three people," prosecutor Tor Børge Nordmo said at a press conference.
The three are adults but much younger than Ludvigsen, and one of them suffers from a mild intellectual disability.
The events took place in his home, countryhouse, hotels and even at the governor's office in Tromso in northern Norway, between 2011 and 2017, according to the charges.
Before becoming regional governor, the former conservative politician held several high-ranking positions, including the post of fisheries minister from 2001 to 2005.
Ludvigsen, who was arrested in early 2018 and released from custody after five weeks, has denied the charges against him.