Handfasting is a betrothal or wedding ritual in which the couple's clasped hands are draped with a cord or ribbon while the couple holds hands. The ‘tying the knot’ is done by the officiant of the ceremony, by the wedding guests, or by the couple themselves.

In Ireland and Scotland, during the early Christian period it was a form of trial marriage, often performed in rural areas when a priest was not available. The couple could form a temporary, trial marriage, and then be married "in the Church" the next time a priest visited their area. In some modern Earth-Based traditions, the ceremony has been reinterpreted to be a spiritual marriage, whether on a trial basis or as a permanent (even eternal) bond.

One historical example of handfastings as trial marriages is that of "Telltown Marriages" - named for the year and a day trial marriages contracted at the yearly festival held in Telltown, Ireland. The festival took place every year at Lughnasadh (August 1), and the trial marriage would last until the next Lughnasadh festival. At that time, they were free to leave the union if they desired.

Earth-Based spirituality handfastings may be for "a year and a day", a lifetime, or "for all of eternity". Whether the ceremony is legal, or a private spiritual commitment, is up to the couple.

As with more conventional marriage ceremonies, couples often exchange rings during a handfasting, symbolizing their commitment to each other. Many couples choose rings that reflect their spiritual and cultural traditions, while others choose plainer, more conventional wedding rings.