Jack and Anne Clark were involved in the single-vehicle crash on Christchurch Akaroa Rd near Little River about 10.40am on April 3.
Police said at the time they were both transported to hospital in a serious condition. Anne died in Christchurch Hospital that afternoon, while Jack passed away on April 5.
The New Zealand Herald reported the couple, who ran the Mulberry House bed & breakfast in Akaroa for 30 years, were remembered as "special humans" at the service on Saturday.
Their granddaughter Charlotte Catherwood told the Herald "whānau, locals and special friends travelled from near and far" for the service.
"Thirty years running a bed & breakfast in Akaroa means that a lot of people showed up," Catherwood told the Herald.
"Forever young at heart, they just loved and understood young people."
The family also shared a statement exclusively with the Herald.
"Their teaching never stopped, even when they retired from their English teaching careers, and the doors to Mulberry House are forever open to friends and family,” it said.
The statement said Jack, who was born in the United States, was "indescribably wise".
"He’s seen it all ... growing up sometimes in a tent as a kid, being stationed in the navy for the US in Hawaii as a young boy, bringing up three boys in the US before moving to New Zealand after meeting Anne, the love of his life and looking after her kids and the rest of our whānau that followed,” it read.
Jack was a former teacher at a Detroit high school. The family statement said he was the "most gentle and patient soul" and Anne was "larger than life", the Herald reported.
The Common Cafe in Akaroa also paid tribute to the couple and closed their doors on the day of the funeral.
"Anne and Jack brightened our days visiting us for their usual flat white and Americano served in their own special cups," the cafe's Facebook page said.
"We will miss Jack’s quick wit and charming smile and Anne’s elegance and generosity. Many of Anne’s gorgeous clothes are proudly worn by the Common staff."
The serious crash unit conducted a scene examination at the time of the crash and a police investigation is under way.
