Valentine’s Day is usually rush hour at Las Vegas wedding chapels, but a bunch of Elvis pastors WILL be lonesome this weekend … due to the pandemic.

According to the Graceland Wedding Chapel … it conducted a whopping 75 ceremonies on V-Day 2020 — just weeks before COVID-19 changed the world — but it only has 50 on the books so far for 2021.

The famous chapel tells TMZ … roughly half its business typically comes from international guests, but with coronavirus travel restrictions that number’s a big, fat zero this year.

Graceland says it hopes to get 60 wedding ceremonies booked before Sunday, but that’s still a significant decline of at least 20 percent.

A rep for Chapel of the Flowers tells us their wedding ceremony bookings are also down 20 percent this year compared to last … but it’s even worse at a couple other spots.

Viva Las Vegas Wedding Chapel says it’s down 50 percent for V-Day, and like Graceland … the lack of international couples is crushing its bottom line. As of now, it says it only has 17 wedding reservations for Sunday … which is incredibly low.

The owner of Bliss Wedding Chapel, which just opened in October, tells us he’s been banking on a Valentine’s Day surge for some much-needed cash … but it’s not happening.

He says he’s been in the biz for a while and would expect a solid 50 ceremonies under normal conditions … but COVID’s limited bookings to just 26, so far.

One thing the chapels cited for their struggles is having to operate at half-capacity. Like the Bliss owner put it — weddings are the opposite of social distancing, so couples who would be forced to cut the guest list are simply opting to wait or go elsewhere.

The good news — Elvis is still in the building. Graceland says couples can still have an Elvis impersonator conduct the legal vows and perform … and he can do it all in a mask