剪接（英语：Splicing，又称拼接），是一种基因重组技术，在分子生物学中是指基因信息在转录后的一种修饰，即将内含子移除及合并外显子。是真核生物的信使RNA/信使RNA前体（precursor messenger RNA）变成成熟mRNA的过程之一。这也是真核生物与原核生物的区别之一（请参看顺反子）。这些成熟的mRNA会接着进行蛋白质生物合成中的翻译，以产生蛋白质，称转译作用。 剪接是核糖核酸（RNA）核苷酸之间的一连串生化反应，并由小核核糖蛋白(snRNP)中的snRNA负责催化并作用。也有一些类型不需外在催化物质，而是在特定二价金属离子存在的情况下，以自我催化方式进行剪接，如第I型或第II型内含子 (type-I or type-II intron)。

In molecular biology, splicing is the editing of the nascent pre-messenger RNA (pre-mRNA) transcript. After splicing introns are removed and exons are joined together (ligated). For nuclear-encoded genes, splicing takes place within the nucleus either co-transcriptionally or immediately after transcription. For those eukaryotic genes that contain introns, splicing is usually required in order to create an mRNA molecule that can be translated into protein. For many eukaryotic introns, splicing is carried out in a series of reactions which are catalyzed by the spliceosome, a complex of small nuclear ribonucleoproteins (snRNPs). Self-splicing introns, or ribozymes capable of catalyzing their own excision from their parent RNA molecule, also exist.