Handfasting is an ancient commitment ceremony. It is the predecessor to the modern wedding ceremony. The ritual itself usually includes a loose binding together of the hands of the couple with a ritual cord of some kind, hence the name, which means "hand fastening." It is also the origin of the slang phrase "to tie the knot."

Handfasting is a symbolic ceremony to honor a couple's desire for commitment to each other; to acknowledge that their lives and their fates are now bound together. it is the word used by the ancient Celts to describe their traditional trial-marriage ceremony, during which couples were literally bound together. The handfasting was a temporary agreement, that expired after a year and a day. However, it could be made permanent after at that time, if both spouses agreed.

Today some couples are choosing to have it be a part of their wedding ceremony.