Are Catholic Trunk-or-Treat parties considered Halloween or All-Saint's-Day parties? Many Catholic churches in the U.S. consider Trunk-or-Treat as a &quot;Christ-centered, safe, family celebration&quot;. With expectations that volunteer workers' costumes &amp; stations allude to biblical stories or saints, Are Catholic Trunk-or-Treat parties considered Halloween or All-Saint's-Day parties?
Are Catholic Trunk-or-Treat parties considered Halloween or All-Saint's-Day parties?
In one sense, they are simply considered parties! However that does not paint the whole picture.
Halloween party festivities are generally not endorsed by the Catholic Church. There is no religious feast day celebrating it.
Up until 1955, the Church’s Liturgical Calendar for the 31st of October celebrated the day as the Vigil of All Saints. That meant purple vestments and generally also was kept as fast day. That sounds like a far cry from a trick or treating party.

In 1955, Pope Pius XII reduced the number to 7, suppressing the vigils of the Immaculate Conception, Epiphany, and All Saints and all vigils of apostles except that of Saints Peter and Paul. In the 1950s Pope Pius XII instituted a reform of the Easter Vigil, first on an experimental basis, then making it obligatory in 1955. Among other changes, he changed the hour of the service from Holy Saturday morning to after sunset in the following night, thus restoring it to something like the original meaning of a Christian vigil service. - Vigil

The whole idea of Halloween parties being considered All Saints Parties will ultimately depend on the local tradition of one’s particular parish living according to Catholic values, that includes the trunk-or-treat parties: some could be considered All Saints Parties , while other are not.

Move over trick or treat, there's a new gig in town and it's called trunk or treat. Originally started by church groups with the aim of providing a safer environment for trick-or-treaters on Halloween, trunk or treat involves a community coming together in a parking lot, either on the 31st or shortly before, so that children can trick-or-treat out of the decorated trunks of their cars.
If trunk-or-treating hasn't hit your town yet, odds are it soon will because the door-to-door alternative is gaining in popularity, owing in part to the convenience inherent in condensing a large volume of candy into a small area (read: less walking), but mostly for the opportunity it affords holiday decor enthusiasts, to get creative with their trunks.
Like anything, however, trunk or treat has its detractors. I for one, feel a little uneasy about this threat to good old-fashioned trick-or-treating. - Trunk Or Treat: New Tradition Could Change Halloween As We Know It

If a particular Catholic community were to hold a trunk-or-treat party and insist that costume wearers should be dressed as saints, then yes that particular party could be considered an All Saints Vigil Party! That means no costumes of devils, demons, witches or the like.
The parish next to my own actually has done this for a few years now. Only saints permitted in and St. Peter is holding the keys to the parking lot!
Another parish community of All Saints has been holding a “Halloween Party” for decades now in their auditorium that has been based on Catholic values. Once again only appropriate saints costumes are allowed in.
In the end, a trunk-or-treat party would only be considered an All Saint Party if it actually sticks to some very basic guidelines, otherwise it just your average happy-go-lucky Halloween Party!
To think that the Church truly endorses the whole concept of Halloween is nonsense, as there is actually nothing in the liturgy to consider it a genuine Catholic festivity.