The base game of Super Smash Bros. Ultimate contains 103 stages.
That figure refers to the stages available in the launch version’s base game, before counting additional stages introduced through downloadable content. Ultimate’s stage roster is unusually large because it brings back many arenas from earlier Smash games while also adding new locations based on franchises such as Splatoon, Super Mario, The Legend of Zelda, and Castlevania.
The number can be confusing because Ultimate continued to receive updates after release. One extra stage was added in a free update, while further stages arrived alongside paid DLC fighters. Depending on whether someone is counting the launch base game, later free additions, or the complete post-release roster, different totals may be quoted.
Ultimate also gives many stages alternate Battlefield and Omega forms. These variants change the layout while retaining the stage’s visual identity, so they are not normally counted as entirely separate stages in the headline total. The stored answer, 103, is therefore the canonical count for the base game’s original stage selection.