It has been more than a month since Richard Dyson, 55, was last seen late on Sunday November 17 in Hoyland.
Police say it would be ‘incredibly out of character’ for Richard not to have contacted his daughter since then.
Detective Inspector Neil Coop from Barnsley CID said: “Tomorrow will be Richard’s birthday and the day after is Christmas - occasions when many of us are with our families and loved ones.
“Richard’s daughter is understandably distraught as it has now been over a month since she last saw her dad, which must be especially difficult at this time of year knowing his birthday and Christmas are upon us.
“I’d like to issue a personal appeal to Richard. Please get in touch with your daughter, let her know that you’re safe for Christmas.
“All any of us want to know is that you’re all right - please make contact with someone and let us know where you are.”
Richard was reported missing on Monday November 25 by his daughter, who last saw him on Friday November 15 at 6pm in the Aston area of Rotherham.
Officers believe Richard was last seen on Sunday November 17 at about 11pm, walking towards the A6135 Sheffield Road in Hoyland, close to Parkside Cottage.
DI Coop said: “We continue to progress any and all lines of enquiry as they come in. Unfortunately, we have not yet been able to confirm any further sightings of Richard but we are very grateful to everyone who has taken the time to submit information and contact police.
“Richard’s daughter really misses him, so I’d ask anyone yet to come forward with information to consider the impact of not doing so on his family.
“No matter how small you might feel your information is, it might be the little piece we need to locate Richard and bring him home.”
Anyone with information can submit it online via the Major Incident Public Portal (MIPP) here.
You can also call 101 quoting incident number 459 of November 25.