Ms Harrington and Mr Allen have considered themselves part of the wider Featherston community since they moved to their South Wairarapa spot, from Wellington, a decade ago.
"We have been supporting Featherston businesses and shopping at the local supermarket for 10 years," Mr Allen said.
"But I know I won't be considered a local until I have been here for a least 100."
He and his partner had seen the historic hotel as an opportunity to create additional accommodation for people attending weddings in South Wairarapa.
"We have a particular interest in heritage buildings," he said. "We have always admired the Royal as we have driven past. It came on the market and we thought it would be a good fit with Tuhitarata Estate."
Although some people considered Featherston to be "the Cinderella of South Wairarapa", he had faith the town would "come into its own".
"We have watched a number of new businesses showing evidence of that.
"There's a movement afoot to push the town to its full potential."
LJ Hooker Masterton owner David McHattie said there had been a lot of inquiries about the building and it took a while to find the "right person".
"It's been a great pub and I think these people will take it to another level.
"[Mr Allen] has got ideas and experience in the hospitality industry," he said.
Mr McHattie said the new venture would be positive for Featherston.
"It's good news for the town."
The Royal Hotel was first built in 1868 during the foundation of the settlement. The large two-storey building was extensively damaged by fire a few years later and was rebuilt in 1893.
Restaurateur and councillor Dean Davies and his late partner Ulli Reinartz, who was chef de cuisine, ran the historic hotel from 2010 until September 2014.
Mr Davies said he wished the new owners all the best.
"I think it's fantastic. It will be good to see the old girl up and running again.
"I know that the locals have been hanging out for it to open so it will be good for them and so great for Featherston."
The Royal Hotel stands at the Rimutaka end of the township.