Norwegian losses April 1940
April 9 Norge torpedoed at Narvik by German destroyers
April 9 Eidsvold torpedoed at Narvik by German destroyers
Submarine B1 scuttled but later raised and used to escape Norwegian personnel to Britain.
German losses 1940
April 8 German transport Rio De Janeiro sunk by submarine Orzel.
April 9 cruiser Blucher sunk in the Oskarsborg Narrows. The Lützow and the Brummer damaged.
April 9 German cruiser Karlsruhe permamently put out of action by the British submaine Truant off Christiansand.
U-1 went missing around Stavanger April 9-16
Königsberg damaged April 9 during the attack on Bergen sunk by RAF Skuas 10 April
First battle of Narvik 2 German destroyers sunk and a further 2 seriously damaged. Eight merchantmen and the ammunition ship Raunfels also sunk. Two British destroyers sunk in return.
April 11 German cruiser Lützow damaged by torpedo from British submarine HMS Spearfish. Lützow out of action for a year.
April 13 and 14 two submarines lost around Narvik and Harstad one U-64 sunk April 13 by a float plane from Warspite the other U-49 sunk by Warspite's escorts 14 April.
April 13 second battle of Narvik all 8 German destroyers wiped out by a force including Warspite, 9 destroyers and planes from the carrier Furious.
The lost destroyers were the Z2 George Thiele, Z9 Wolfgang Zenker, Z11 Bernd von Arnim, Z12 Erich Giese, Z13 Erich Koeller, Z17 Diether von Roeder, Z18 Hans Lumann, Z19 Herman Kunne, Z21 Anton Schmitt, and Z22 Wilhelm Heidkamp.
Narvik campaign
April 29 the German torpedo boat Leopard lost after colliding with the Minelayer Preussen.
British losses in Norway in April 1940
Sloop Bittern
April 8 British destroyer Gloworm lost in action against the Hipper. The British destroyer rammed the Hipper before sinking.
April 9 British destroyer Gurkha lost in an air attack.
April 10 two British destroyers lost, the Hunter sunk and the Hardy run aground in the first battle of Narvik, two other destroyers badly damaged.
April 13 destroyer Eskimo loses her bow in the second battle of Narvik.
April 17 the heavy cruiser Suffolk badly damaged after shelling Sola airfield.
April 19 French cruiser Emile Bertin withdrawn after receiving a hit from a German bomb.
British losses in Norway in May 1940
The Tribal class destroyer HMS Afridi, and the French super destroyer Bison lost in air attacks 2/3 May. Afridi lost off Namsos.
Polish destroyer Grom lost 5 May.
HMS Effingham a Hawkins class Cruiser wrecked off Norway and sunk by the Royal Navy May 18.
May 26, 1940 light anti aircraft cruiser Curlew sunk off Harstad.
Destroyer HMS Jaguar bombed during evacuations in late May.
May 7, 1940
HMS Kelly torpedoed, eventually towed into port
Sub losses off Norway
| April | Thistle, Tarpon, Startlet |
| May | Seal, Orzel(Po) |
| June | 0.13(Du) |
| July | Shark, Salmon, Thames, Narwhal |
| August | Spearfish |
Thistle was sunk by U-4 on April 10. Tarpon lost 14 April, Seal mined May 4, captured by a German plane and trawler, Salmon was lost between 4-7 July. Narwhal lost between 22-28 July, Spearfish was sunk by U-34 August 1, though was not reported missing for several days. Thames was a river class submarine.