| 1938 Norwegian Football Cup | |
| Other Titles: | Norgesmester i fotball for menn 1938 |
| Country: | Norway |
| Num Teams: | 128 (main competition) |
| Defending Champions: | Mjøndalen |
| Winners: | Fredrikstad (3rd title) |
| Second: | Mjøndalen |
| Prev Season: | 1937 |
| Next Season: | 1939 |
The 1938 Norwegian Football Cup was the 37th season of the Norwegian annual knockout football tournament. The tournament was open for all members of NFF, except those from Northern Norway. The final was played at Briskeby in Hamar on 16 October 1938, and was contested by the defending champions Mjøndalen and the three-time former winners Fredrikstad. Fredrikstad secured their fourth title with a 3–2 win after extra time in the final. Fredrikstad's cup-victory completed the first Norwegian double, having also won the inaugural League of Norway.
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See main article: 1938 Norwegian Football Cup final.