The Gankyil (Tibetan: དགའ་འཁྱིལ།, Lhasa [kã˥ kʲʰiː˥]) or "wheel of joy" (Sanskrit: ānanda-cakra) is a symbol and ritual tool used in Tibetan and East Asian Buddhism. It is composed of three (sometimes two or four) swirling and interconnected blades. The traditional spinning direction is clockwise (right turning), but the counter-clockwise ones are also common.

The gankyil as inner wheel of the dharmachakra is depicted on the Flag of Sikkim, Joseon, and is also depicted on the Flag of Tibet and Emblem of Tibet.

In addition to linking the gankyil with the "wish-fulfilling jewel" (Skt. cintamani), Robert Beer makes the following connections:

The gakyil or 'wheel of joy' is depicted in a similar form to the ancient Chinese yin-yang symbol, but its swirling central hub is usually composed of either three or four sections. The Tibetan term dga' is used to describe all forms of joy, delight, and pleasure, and the term 'khyil means to circle or spin. The wheel of joy is commonly depicted at the central hub of the dharmachakra, where its three or four swirls may represent the Three Jewels and victory over the three poisons, or the Four Noble Truths and the four directions. As a symbol of the Three Jewels it may also appear as the "triple-eyed" or wish-granting gem of the chakravartin. In the Dzogchen tradition the three swirls of the gakyil primarily symbolize the trinity of the base, path, and fruit.

— Robert Beer, The Handbook of Tibetan Buddhist Symbols

The "victory" referred to above is symbolised by the dhvaja or "victory banner".

The divisions of the teaching of Dzogchen are for the purposes of explanation only. Realization is not something that must be constructed; to become realized simply means to discover and manifest that which from the very beginning has been our own true condition: the Zhi (gzhi) or Base. And, in particular, in Dzogchen－which not a gradual Path－the Path consists in remaining in the unveiled, manifest condition of the primordial state or Base, or in other words, in the condition which is the Fruit. This is why the Gankyil, the symbol of primordial energy, which is a particular symbol of the Dzogchen teachings, has three parts which spiral in a way that makes them fundamentally one. The Gankyil, or "Wheel of Joy", can clearly be seen to reflect the inseparability and interdependence of all the groups of three in the Dzogchen teachings, but perhaps most particularly it shows the inseparability of the Base, the Path, and the Fruit. And since Dzogchen, the Great Perfection, is essentially the self-perfected indivisibility of the primordial state, it naturally requires a non-dual symbol to represent it.

Wallace (2001: p. 77) identifies the ānandacakra with the heart of the "cosmic body" of which Mount Meru is the epicentre: