[1] After the outbreak of the Second World War, Odin formed part of the 3rd destroyer section in the Kristiansand Defence Sector of the 1st Naval District.

[4] On 8 April 1940, she had taken part together with the guard ship Lyngdal in the rescue of the surviving sailors and soldiers from the 5,199 ton clandestine German troop transport Rio de Janeiro[5][6][7] sunk by the Polish submarine ORP Orzeł near the small port of Lillesand.

The next morning, 9 April 1940, Odin took part in the defence of Kristiansand, against landing group four of the German invasion of Norway.

[8] At about 07:30 a twin-engined aircraft attacked the interned German submarine U-21 that was docked in Kristiansand harbour, having been seized by Norwegian warships for neutrality violations after running aground on the Oddene shallows near Mandal 27 March that year.

This order, combined with confusion of which flags were flown by the intruding warships, led to the German force being able to enter the harbour unopposed on their third attempt at 10:30.