Commissioner v. Glenshaw Glass Co., 348 U.S. 426 (1955), was an important income tax case before the United States Supreme Court.

The Court held as follows: Two factually distinct cases were consolidated because they presented the same issue.

The Supreme Court, in an opinion by Chief Justice Earl Warren, held that the award of treble damages was taxable income.

In the opinion, Warren pointed out that the language of section 22(a) (the predecessor of current section 61(a)[2]) was employed by Congress in order utilize "the full measure of its taxing power," as provided for under the Sixteenth Amendment.

Essentially, Congress, in enacting section 22(a), intended to tax all gains except those specifically exempted.