It's known as an orphan Christmas — cheery gatherings at a time typically spent with family and friends, attended by strangers who can't be with either.

Mental health service providers say the Christmas period is "consistently busy" for their hotlines, suggesting it is a vulnerable period for Australians navigating the festive season alone.

Amid this trend, people in Australia's major cities are increasingly throwing open their doors to others this Christmas.

This is what some of them have planned.

Elizabeth Ferguson, Brisbane

Elizabeth Ferguson is searching for someone to join her family's Christmas lunch. ( ABC: Hailey Renault )

Massage therapist Elizabeth Ferguson took to social media earlier this month to find a stranger to adopt this Christmas.

The empty-nester posted this message to a Forest Lake community page:

"Hi. I am hoping to find someone that would like to share Xmas lunch with us here in Forest Lake on Xmas Day. There will be four adults in their 60s and one in his 80s. "I was thinking of someone who is on their own and [has] nowhere to go, someone that might not be able to have a nice Xmas lunch due to finances. "Everything provided including yummy sweets of course. Let me know and we can discuss further. This is a genuine offer."

Ms Ferguson said she always wanted to open her home to the lonely and less fortunate but had been discouraged by concerned family members in the past.

"When my parents died many years ago my first Christmas was very sad," she said.

"I had two empty seats at the table and it happened to be the same year my kids couldn't come to Christmas lunch because they were with extended family.

"We were blessed to have a roof over our head and lovely food and gifts for each other ... but still felt we could share it with others that weren't so fortunate."

She was on the verge of giving up the search when two strangers responded to a last-minute callout on ABC Radio Brisbane — Sandra, a 63-year-old Spring Lake resident and John, a 75-year-old from Forest Lake.

Ms Ferguson said she was thrilled to lay out two extra places at her table.

"Sandra lives on her own ... and she sounds like a ball of fun; John just put his wife into a nursing home and you can imagine how he would be feeling at the moment."

Next year Ms Ferguson plans to start a register to connect people spending Christmas alone with families willing to open their homes.

Nadeem Turkia, Darwin

Mr Turkia is quite the cook; he runs a food van in Darwin and Palmerston. ( ABC News: Kristy O'Brien )

Nadeem Turkia comes from one of about four Syrian families currently living in Darwin.

This year he's planning a Christmas lunch that will put his culinary skills to good use.

Geared towards Darwin's itinerant population of immigrants and contract workers, the event will be a change of pace from the typically close-knit family lunches he's used to.

With his friend Daniello, an Italian man facing his first Christmas away from his family, Mr Turkia has hatched plans for what he's labelling "Darwin's first multicultural Christmas festival".

"A lot of people that work in Inpex or other places, they don't have families, and they just fly to Darwin without any families," Mr Turkia said.

"We started to think about it; we get to prepare the Mexican food, Spanish food, Italian food, Middle Eastern food and African food."

The pair also hope to arrange family activities and salsa dancing.

Jessica Ardaiz, Canberra

Jessica Ardaiz is set to prepare lunch for more than 100 people who might otherwise spend Christmas alone. ( ABC Canberra: Hannah Walmsley )

Canberra chef Jessica Ardaiz will be serving up a festive feast at Leumeah Lodge in the city's north on Christmas Day.

"It's a great way for me to show my children what it is to be part of a community," she said.

"The kids will be there helping too."

Local charities Oz Harvest, YMCA and Canberra City Care have teamed up to put on the free lunch.

"It's a day for community connection, where people can come together and share their story whatever it may be," Ms Ardaiz said.

"There's going to be lots of food."

Dave Burnett from Oz Harvest said there would be more than enough Christmas pudding for everyone.

In Canberra, Oz Harvest rescues around 35,000 kilograms of food each month.

"It's all within date and all beautiful, it's just excess to requirement," Mr Burnett said.

"Locally, we look after 67 charities and we'll be able to give them plenty of Christmas stuff as well.

"There are a lot of people out there who are just lonely.

"A lot of us have families who get together, but we sometimes forget about the people who do live on their own."

Canberrans interested in attending the lunch can contact Canberra City Care to register.

Tejinder Singh, Darwin

Mr Singh will take his van on a familiar delivery route on Christmas Day. ( 105.7 ABC Darwin: Emilia Terzon )

Tejinder Singh is used to slaving away behind large vats of chickpea and lentil curries which the taxi driver then delivers to a well-travelled circuit of Darwin's homeless.

But on Christmas Day this year his menu will be a little more tailored.

"I cook a special menu up on Christmas. I also decorate my van like Santa Claus ... I go around everywhere. My first target is to look after local, native people," he said.

Mr Singh said he doesn't celebrate Christmas.

Instead, his delivery route honours the tenet of his own religion, Sikhism.

"I want to spread brotherhood and world peace; I want to share my culture and create for another culture and share, so that's a good way to do that."