Alice Brindley, from Ixworth Thorpe, Suffolk, had spent the day in Cambridge with friends and was supposed to catch a train home on Sunday evening.
But instead of boarding a service to Stowmarket, Suffolk, it is believed she got on a train to Islington, London after she called a friend from a payphone there.
Her father, Paul Brindley, 52, tweeted a picture of his daughter and asked people to share it.
He wrote: ‘Can everyone please retweet my lovely little girl has gone missing any help to find her would be greatly appreciated to bring her home.’
Can everyone please retweet my lovely little girl has gone missing any help to find her would be greatly appreciated to bring her home. https://t.co/vt0whargNW
— Paul Brindley (@paulb5261) March 20, 2017
She was last seen yesterday at Cambridge train station around 6.30pm.
Paul, who is an executive director for ExCeL London, said Alice had been with two friends who she has known for years.
Please help me find my little girl. I need her home and safe 💔 please help her find her way home xx please retweet x https://t.co/MrapqoG9UH
— Sarah Brindley (@SarahBrindley7) March 20, 2017
But he said each friend was under the impression Alice was travelling home with the other.
Her mother Sarah, 48, added: ‘She’s just a teenager who can get grumpy but doesn’t go off to London without telling anyone.
‘We’re just desperate for her to come home. We want her to know we love her very much and there’s nothing we want more than to know she’s safe.’
Alice is described as white with collar-length red hair.
At the time she was last seen, she was wearing black skinny jeans and a black hoodie with a grey sheepskin top underneath the hoodie.
She was also wearing a pair of black trainers and carrying a black leather rucksack bag with gold coloured zips.
Police officers are asking anyone who may have seen Alice or has any information about her whereabouts to contact Suffolk Constabulary on 101.