The katara or suwaiya (Tamil: கட்டாரி kaţţāri, Marathi: कट्यार katyaar, Hindi: कटार kaţāra, Panjabi: kataar) is a type of push dagger from India. It is characterised by its H-shaped horizontal hand grip, which results in the blade of the sword sitting above the user's knuckles. Unique to South Asia, it is the most famous and characteristic of Indian daggers. Ceremonial katara were also used in worship.

The katara originated in Tamil Nadu where its Dravidian name was kattari before being altered to katara in the north. The earliest forms occur in the medieval Deccan kingdom of Vijayanagara. Katara dating back to this period often had a leaf- or shell-like knuckle-guard to protect the back of the hand, but this was discarded by the latter half of the 17th century.^{[citation needed]} The Maratha gauntlet sword or pata is thought^[who?] to have been developed from the katara. As the weapon spread throughout India it became something of a status symbol, much like the Southeast Asian kris or the Japanese katana. Among the Rajputs, Sikhs and Mughals, princes and nobles were often portrayed wearing a katara at their side. This was not only a precaution for self-defense, but it was also meant to show their wealth and position. Upper-class Mughals would even hunt tigers with katara. For a hunter to kill a tiger with such a short-range weapon was considered the surest sign of bravery and martial skill.

A dagger is a fighting knife with a sharp point designed or capable of being used as a thrusting or stabbing weapon. The design dates to human prehistory, and daggers have been used throughout human experience to the modern day in close combat confrontations. Many ancient cultures used adorned daggers in ritual and ceremonial purposes, a trend which continues to the present time in the form of art knives. The distinctive shape and historic usage of the dagger have made it iconic and symbolic.

Over the years, the term 'dagger' has been used to describe a wide variety of thrusting knives, including knives that feature only a single cutting edge, such as the European rondel dagger or the Persian pesh-kabz, or, in some instances, no cutting edge at all, such as the stiletto of the Renaissance. However, over the last hundred years or so, authorities have recognized that the dagger, in its contemporary or mature form, has come to incorporate certain definable characteristics, including a short blade with a sharply-tapered point, a central spine or fuller, and (usually) two cutting edges sharpened the full length of the blade, or nearly so. Most daggers also feature a full crossguard to keep the hand from riding forwards onto the sharpened blade edges. Another distinctive feature of the modern dagger is that it is designed to position the blade horizontally when using a conventional palm grip, enabling the user to slash right or left as well as thrust the blade between an opponent's ribs. The twin full-length edges enable the user to make broad slashes (cuts) using either a forehand or backhand arm movement, while the sharp, acutely-pointed tip makes the knife an effective thrusting or stabbing weapon. This versatility distinguishes the modern dagger from more specialized thrusting knives, such as the stiletto.