Ornamental plants, also known as garden plants, are plants that are primarily grown for their beauty, rather than for functional purposes such as food or shelter. They are grown for the display of aesthetic features including flowers, leaves, scent, overall foliage texture, fruit, stem and bark, and aesthetic form. Some ornamental plants are foliage plants grown mainly or entirely for their showy foliage, especially true of houseplants. Ornamental plants are the keystone of ornamental gardening, and they come in a range of shapes, sizes, and colors suitable to a broad array of climates, landscapes, and gardening needs.

Ornamental plants have a long history, with evidence of ornamental gardening dating back at least 4,000 years. The term "ornamental plant" is used in the horticultural trades, in which they are often just called "ornamentals". While some plants are both ornamental and functional, people usually use the term “ornamental plants” to refer to plants which have no value beyond being attractive, although many people feel that this is value enough.

Ornamental plants have a variety of uses beyond their beauty. For example, some ornamentals can be used for medicinal purposes, such as rosemary, Mexican marigold, and lemon grass. Ornamental trees can provide shade, and outdoor ornamentals can help beautify the landscape and create an appealing environment. Fallen leaves from ornamental trees can also make good mulch and compost. Additionally, ornamental plants can brighten a yard, compliment the style of a house or building, and increase its worth.

Overall, ornamental plants are an important part of gardening and landscaping, providing beauty and aesthetic appeal to outdoor spaces.