At its simplest, a turtleneck is a knit top or sweater with a tall, close-fitting collar that covers most of your neck. Some collars fold down once or twice; others are a single, structured layer. You’ll find turtlenecks in lightweight tees, ribbed base layers, and cozy sweaters, so they can work for layering or wearing solo.

• Full turtleneck: taller, often fold-over collar.
• Mock neck: shorter collar that doesn’t fold as much.
• Thermal/base layer styles: slim fits designed for warmth.

When you’re browsing, you can use filters like sleeve length, fit, and material to narrow in on the style that feels right for you.

The name is descriptive rather than technical. “Turtleneck” refers to the tall, close collar that surrounds the neck—essentially a built-in layer that helps keep your neck covered in cooler weather. Over time, the term became shorthand for any top or sweater with that extended neckline.

• Some collars are designed to fold or “roll” down; others stay upright.
• Collar height and snugness can vary by style and fabric.
• Listings may also use “mock neck” for a similar look with a shorter collar.

If you’re comparing options, check the product photos and description for collar height and whether it’s meant to fold, so you can choose the look you prefer.

You’ll often see similar styles labeled with slightly different names. The most common alternatives you’ll find while shopping are:

• Mock neck: a shorter, standing collar that gives the look of a turtleneck without the full fold-over height.
• High neck: a general term indicating a higher neckline; the collar may be shorter and may not fold.
• Turtle neck: the same style as “turtleneck,” just written with a space.

Product pages typically note collar height and fabric, which can help you decide. If you’re searching, try terms like “turtleneck,” “mock neck,” or “high neck” to see the full range of options and find the neck height you like.

In the U.S., “turtleneck” is the everyday term for tops and sweaters with a tall, close-fitting collar that covers most of the neck. You’ll also see related terms used to describe variations.

• Turtleneck: typically the taller collar, often designed to fold.
• Mock neck/mock turtleneck: a shorter collar that stands up without as much fold.
• High neck: a catchall for elevated necklines that may be shorter.

When browsing, these labels can help you sort by collar height and feel. If you’re unsure, check the photos to see how far the collar extends up the neck and read the fit notes in the description.

Choosing the right turtleneck size depends on your preferred fit and the fabric’s stretch. A simple approach:

• Check the size chart: compare your measurements to the chart on the product page.
• Consider fit intent: slim base layers are designed close to the body; relaxed sweaters have more ease.
• Mind the fabric: ribbed knits and stretchy blends tend to be more forgiving; structured knits may feel snugger.
• Review garment measurements: look at chest, shoulder, and sleeve length for the best match.
• Between sizes? Sizing up can add room, while sizing down creates a sleeker layer—results can vary by style.

Filters for size, fit, and material can help you quickly narrow options.