植树造林（英文：Afforestation、Forestation）为在没有森林覆盖的区域中，透过栽植树苗、林木育种等人为方式，使之逐渐成为树林或森林地。

在全球，有许多国家的政府或是非政府组织目前从事造林工作，种植森林的好处是能提高对于环境中二氧化碳的吸存量，并可以人为的方式维持生物多样性。（在英国，植树造林可能意味着一些造林地的法律地位将转变为「皇家森林」。）

一些植树的专门用具，如植树杆，可以使植树造林的工作更加简便与快速。

Afforestation is the establishment of a forest or stand of trees in an area where there was no forest. Reforestation is the reestablishment of forest cover, either naturally (by natural seeding, coppice, or root suckers) or artificially (by direct seeding or planting). Many governments and non-governmental organizations directly engage in programs of afforestation to create forests, increase carbon capture and sequestration, and help to anthropogenically improve biodiversity. (In the UK, afforestation may mean converting the legal status of some land to "royal forest".) Special tools, e.g. tree planting bar, are used to make planting of trees easier and faster.