The next morning, 9 April 1940, Odin took part in the defence of Kristiansand, against landing group four of the German invasion of Norway. When the battle at Kristiansand between the Kriegsmarine flotilla and Odderøya Fort began Odin steamed out into the Toppdalsfjord and opened up on attacking Luftwaffe bombers with her Oerlikon 20 mm cannon and two 12.7 mm anti-aircraft machine guns. Continuous evasive manoeuvring saved the destroyer from being hit by the many bombs dropped at her and several hits were recorded on the attacking aircraft. One of Heinkel He 111s fell to the sea while returning home with engine malfunction, probably due to the Odin's fire. At about 07:30 a twin-engined aircraft attacked the interned 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.Steen 1954: 103 U-21 had been docked in Kristiansand since 28 March.Sivertsen 2001: 69 Odin fired at the aircraft, only to discover it was a RAF Lockheed Hudson reconnaissance aircraft. Neither this time did the Odins fire bring her target down. At 10:00 an order not to fire at British and French forces came to the commander of Kristiansand. 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. Odin was captured at Marvika naval station together with numerous other naval vessels in the Kristiansand area, including her sister ship .Berg 1997: 19HNoMS Odin Krigsseilerregisteret
