.jpg)
St Mary and St Peter Church in St Helier and St Patrick in St Clement will both shut after the usual Sunday Mass on 12 July.
The move was agreed by the Bishop of Portsmouth, who looks after the Catholic church in Jersey, after the parish consulted parishioners in November 2025.
The Diocese of Portsmouth said it spent 17% of the parish budget on maintaining buildings and 11% on running them in 2024-25, whilst income dropped by nearly 6% and donations through the offertory had declined by 37% over the last five years.
The diocese said all seven of the island's Catholic churches hold "a cherished place in the life of our parish".
A spokesperson added: "The potential closure of a church is not taken lightly, and should be approached with prayer, discernment and respect for the impact it may have on those with whom we form our one island Catholic parish."
The diocese said the two church closures "will enable us to focus our resources" to "better serve" the five other churches and would "release financial resources, both in terms of the money currently spent keeping these churches open and funds from a possible sale", to support its mission and parish on Jersey.
It added "we have started to come together much more than we used to" for services and Christmas and Easter celebrations after the three Catholic parishes merged in 2009.
St Mary and St Peter Church, which is one of the churches to close is within a mile of the island's largest Catholic church St Thomas' Church in St Helier, which is attended by three quarters of the parishioners who go to Mass.
The closures mean the Polish Sunday morning mass will move to Our Lady's Church in St Martin and a Sunday evening English mass will cease as the parish clergy, pastoral council and finance committee, agreed that six Sunday Masses in English was enough, parishioners were told.