An uplifting and heartwarming story about finding the magic of Christmas, no matter where you might be, This Is Christmas follows Adam (Alfred Enoch) and Emma (Kaya Scodelario) as they make their daily commute from the picture-perfect village of Langton to London for work. Every day they share their journey with the same characters, but they all keep themselves to themselves. But then one day, in the build-up to Christmas, Adam breaks the unwritten rule of travel and starts talking to the strangers on the train, inviting the whole carriage to hold their own Christmas party.

In his Scottish New Town home, gangling Gregory and his school-friends are starting to find out about girls. He fancies Dorothy, not least because she has got into the football team - and is a better player than him. He finally asks her out, but it is obviously the females in control of matters here, and that very much includes Gregory's younger sister.

梅尔文是位成功的英国作家，他的家庭是个有些古怪却典型的英国加勒比大家庭，衣食无忧且有兄弟姐妹围绕。几年前，他与家人共同度过节礼日时发生了尴尬的事件，此后为了逃避家人，他搬到了美国。这一年，为了宣传他的新书，也为了借这个好机会介绍他的美国未婚妻丽莎给家人认识，丽莎是位迷人的事业女性，二人十分合拍。梅尔文回到了伦敦的家中过节，与家人们一起拆礼物。但想要欢度圣诞似乎并没有那么容易，他发现自己被卷入了家庭闹剧，起因还是围绕着他那现在已经是国际流行巨星的前女友乔治雅，乔治雅是他的青梅竹马，似乎对他余情未了。这一次，不仅他与家人的关系再次受到了挑战，他与未婚妻的感情也经受着考验，这个节礼日变得不同寻常起来。