No, it isn’t. At least, not in the United States. On the other hand, a font IS protected by copyright.
Does this seem confusing? If so, it’s because so many people use the term “font” to refer to a “typestyle” or “typeface.” The two terms are really not interchangeable.
A typeface, or typestyle, is a set of letters, including numbers, punctuation and assorted glyphs, that all share similar design characteristics. They may have similar shapes, strokes, serifs and other details. In printed form, they all look to be part of the same family due to their design. In the United States, a letterstyle does not qualify for copyright registration.
So what is a font? Though many people use the word ‘font’ as a synonym for letterstyle, it is really what is used to produce letters in a form that can be viewed. A font is a piece of software, a program really, that allows a computer to command a printer (or router, or laser engraver, or embroidery machine) to produce the letters in physical form. Originally, a font was a set of metal type pieces in a particular size and typestyle for loading onto a printing press. To create a complete font of type was labor-intensive and expensive. Nowadays, a font is generally composed of unique digital code. This code is protected by copyright, and it cannot be copied without permission from the copyright owner.
Additionally, font names can be protected by trademark law, just like brand names. This is why you can buy a font (actually, a license to use the font) for your computer for printing letters that look exactly like Helvetica, but they are called something else. Someone owns the Helvetica font, the name and the underlying software, and that’s not the license you bought. You bought a license to use a differently programmed piece of software with a different name. But what you print looks just like Helvetica letters, because the Helvetica font owners don’t own what the letters look like, the design.
Of course, this is US law. The laws on fonts and typestyles may and does vary in other countries.