An ambry (or almery, aumbry; from the medieval form almarium, cf. Lat. armārium, "a place for keeping tools"; cf. O. Fr. aumoire and mod. armoire) is a recessed cabinet in the wall of a Christian church for storing sacred vessels and vestments. They are sometimes near the piscina, but more often on the opposite side. The word also seems in medieval times to have been commonly used for any closed cupboard or even a bookcase.

Items kept in an ambry include chalices and other vessels, as well as items for the reserved sacrament, the consecrated elements from the Eucharist. This latter use was infrequent in pre-Reformation churches, although it was known in Scotland, Sweden, Germany and Italy. More usually the sacrament was reserved in a pyx, usually hanging in front of and above the altar or later in a "sacrament house".

After the Reformation and the Tridentine reforms, in the Roman Catholic Church the sacrament was no longer reserved in ambries; some ambries were used to house the oil for the Anointing of the Sick. Today in the Roman Catholic Church, the consecrated elements may only be reserved in a tabernacle or hanging pyx; reservation in an ambry is now forbidden.

The Reformed churches abandoned reservation of the elements, so that ambries, unless used for housing vessels, became redundant. But, in the Scottish Episcopal church since the eighteenth century and other Anglican churches since the nineteenth century (following the Tractarian revival), reservation has again become common. In the Church of England the sacrament is reserved in all forty-four cathedrals, as well as many parish churches, although it is very uncommon amongst churches of an evangelical tradition. Reservation of the sacrament is quite common in the Episcopal Church of the United States, the Anglican Church of Australia, the Anglican Church in Aotearoa, New Zealand and Polynesia, the Anglican Church of Southern Africa, as well as in the Anglican Church of Canada (though with varying degrees of veneration, depending on the parish). Even some traditionally Low Church parishes, such as St. Anne's, Toronto, reserve the sacrament.