Ship commissioning is the act or ceremony of placing a ship in active service and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to placing a warship in active duty with its country's military forces. The ceremonies involved are often rooted in centuries-old naval tradition.

Ceremonial ship launching involves the performance of ceremonies associated with the process of transferring a vessel to the water. It is a nautical tradition in many cultures, dating back millennia, to accompany the physical process with ceremonies which have been observed as public celebration and a solemn blessing, usually but not always, in association with the launch itself.