St Thomas’, in Elson Road, was broken into between 8pm on Wednesday and 11.30am Thursday.
A spokesman for Hampshire police said: ‘A door was forced open and silverware was stolen from a safe. Items taken include two chalices with an engraving on the bottom stating “St Thomas”, and a Peugin Flagon jug.
Hampshire Constabulary has now launched an appeal for help to track down the thieves.
Anyone with information on the items, or who sees them for sale, can call police on 101, quoting the reference 44180079328.