The school was founded by the Daughters of the Cross in 1893[3] and is situated in twenty-five acres of parkland with some notable buildings.

[4] Other owners included Sir John Fellowes, 1st Baronet, Sub-Governor of the South Sea Company; Lord Anson, admiral; and Philip Yorke, 1st Earl of Hardwicke, Lord High Chancellor.

In 2007, a new Learning Resource Centre, including a library, was opened.

[citation needed] In 2016, a new classroom block, the Veritas Centre opened.

In April 2012, a student reported St Philomena's to PinkNews for urging its pupils to sign an anti-gay marriage petition in protest at the government's proposal to allow gay couples to marry in civil ceremonies.