18-year-old Amber Phillipson was reported missing on Tuesday and there understood to have been no confirmed sightings of her since then.
Her dad Dave Phillipson has issued the bumper cash reward via Facebook.
He wrote on his page: "£5,000 reward for the finding of Amber Jade Phillipson.
"Help people - Amber is missing and I am genuinely worried for her safety.
"And if Amber's reading, come home hun let’s sort our lives out plzzzzzz."
A spokesman for South Yorkshire Police confirmed that Amber was reported missing at around 10.30pm on December 19.
She is thought to have left an address on Grampian Way, Thorne at around 9pm the same evening.
It is understood that she left both her cars and phone at home.
Her dad added on Facebook: "If any body at her college knows anything or at Boots (on Wheatley Hall Road where she works) plz let me know, feels like I have died inside with worry plz HELP X"
Anyone who has seen or heard from Amber since Tuesday is asked to call 101 quoting incident number 1072 of 19 December.