The neckline is the top edge or edges of a garment that surrounds the neck, especially from the front view. Neckline also refers to the overall visual line between all the layers of clothing and the neck and shoulders of a person, ignoring any unseen undergarments.

For each garment worn above the waist, the neckline is primarily a style line and may be a boundary for further shaping of the upper edge of a garment with, for example, a collar, cowl, darts, or pleats. In that respect it is similar to the waistline and hemline.

Necklines can be grouped into categories according to their shape and where they cut across the body.

The boat neck, also called the bateau neckline or Sabrina neckline, is a high, wide, slightly curved neckline that passes past the collarbones and hangs on both shoulders. It has one edge and is nearly linear. The portrait neckline is a variation of this.

This neckline is circular and sits at the base of the throat, with a rib knit band around the neck. It is commonly called the T-shirt neckline. It's functionally interchangeable with the jewel neckline, though jewel tends to refer to a neckline that does not include the rib knit band.

These are low necklines, in either V, U, or square shapes, that reveal some amount of cleavage. Evening gowns often have low necklines. In some cases, such as Elizabeth Hurley's famous black dress and the blue Prada dress of Lupita Nyong'o, these necklines will extend to the natural waistline.

One extreme example of a plunging neckline is the green Versace dress of Jennifer Lopez, which has a neckline that extends down past the navel.

The funnel neckline, sometimes called the built-up neckline, has fabric standing high and close to the neck, cut or knit in one piece with the torso rather than as an added collar.