笔名是有些作家发表文章时，基于某种理由不以真实姓名发表而采用的化名。

各个作家都有不同使用笔名的原因。有些作家取笔名是为了发表作品时能够隐藏自己真正的身份，或是因为作家认为自己的本名不够响亮、或者与作品风格不相符而刻意取适合自己文风的笔名；有些作家则是在不同风格作品的发表上使用不同的笔名加以区别；有些则是两人或多人共同创作而取一笔名当代表。笔名可视为一种品牌，有些作家或出版社会向政府将自己的笔名登记为注册商标。

A pen name, nom de plume (/ˌnɒm də ˈpluːm/, French: [nɔ̃ də plym]), or literary double is a pseudonym adopted by an author. A pen name may be used to make the author's name more distinctive, to disguise his or her gender, to distance an author from some or all of his or her previous works, to protect the author from retribution for his or her writings, to combine more than one author into a single author, or for any of a number of reasons related to the marketing or aesthetic presentation of the work. The author's name may be known only to the publisher, or may come to be common knowledge.