抄袭（英语：plagiarism），亦称作剽窃，根据教育部国语辞典定义，为抄录他人作品以为己作。对于原着未经或基本未经修改的抄录，这是一种侵犯著作权的行为。

有时抄袭之认定较难以做出客观判断，必须经过主观判断，例如模仿一个故事的情节是否属抄袭就有很大争议，一些人认为故事情节属于思想范围，而“抄袭思想”并不是侵权的行为，因为法律只保护思想的表现方式，而不是思想本身。有些抄袭行为虽未达到客观上的侵犯权利(例如:部分抄袭行为在法律上并不违法)，但是在学术界或相关领域，则是严重的违背道德良知行为。不当的抄袭行为，可能导致学位、褒奖、职务或是认证的撤销，严重者恐面临法律诉讼及求偿。

Plagiarism is the "wrongful appropriation" and "stealing and publication" of another author's "language, thoughts, ideas, or expressions" and the representation of them as one's own original work. The idea remains problematic with unclear definitions and unclear rules. The modern concept of plagiarism as immoral and originality as an ideal emerged in Europe only in the 18th century, particularly with the Romantic movement.