The charity Missing People wants to raise awareness of the disappearances of Megan Roberts, from Wetherby, West Yorkshire, and Ed Machin, from York.
Miss Roberts, 20, went missing in York on 23 January. Police say it is likely she fell into the River Ouse.
Mr Machin, 39, was last seen on the same day in Bempton, East Yorkshire. Their disappearances are not connected.
Fans at the League Two match between York City and Cheltenham Town were also reminded of the search for York chef Claudia Lawrence.
Miss Lawrence was last seen on 18 March 2009, when she was aged 35. Detectives believe she was murdered.
Martin Crosby, from Missing People, said: "When someone you love goes missing you want the whole world to stop and join the search.
"Sharing these appeals is one of the key ways fans and the public can support the search for Megan, Claudia and Edward, whose family and friends are pleased to work on this with York City FC, as a club at the centre of the community."
Miss Roberts, who is studying at York St John University, was last seen near to Lendal Bridge which crosses the River Ouse.
North Yorkshire Police have said the "strongest and most probable line of inquiry being pursued by police is that Megan, affected by alcohol, has entered the river".
Mr Machin was last seen in Bempton, near Bridlington, after he was dropped off by a taxi outside the White Horse Inn.
Miss Lawrence's father Peter was expected to attend the event.
He said: "It is distressing to have both Edward and Megan missing in York along with Claudia and my thoughts are with their families and friends.
"I would encourage as many people as possible to help the charity by volunteering, sharing the appeals and by signing up to receive alerts at the game on Saturday."
An appeal for help to find a student and a man missing since January has been made at York City's ground.