The grotto has been set up at Little Big Village, in Locks Heath Shopping Village, and despite the looming possibility of tighter Covid restrictions, the event has proved popular, according to owner Sarah Goddard.
Sarah said Father Christmas will be at the cafe every day until Christmas - and she urged people to get in touch if they'd like to attend to get on the centre's waiting list.
The original dates sold out within two hours, but as people cancel plans due to sickness or uneasiness, some slots have opened up.
Sarah, who opened the centre last year with husband Nick, said: 'We have seven days of Santa and over that time we have 429 children booked in to come and see him.
'The two days we have run so far have been very successful. Yes people are nervous about Covid, but this is something nice for the children and we have safety measures in place, so they have still been coming to see us. We are very grateful for their support.
'It has been lovely and everyone has been pleased to have somewhere to go that is nice and festive.
'Father Christmas has been amazing. We are so lucky he has been able to take time out of his busy schedule to come and see our children.'
Lots of families were enjoying the festivities over the weekend.
Mike McVean, from Fareham, was at the play cafe on Saturday with his fiancée Helen Sutton and their four-year-old son James.
Mike said: 'Father Christmas was very kind and very engaging with the kids. It was a nice set-up, he even welcomed us when we first came in through the door. Little Big Village is great, we come here a lot as it is clean, not too crowded and the staff are very nice.'
Sarah thanked Blake's Entertainment, a Southampton-based business, for providing the main attraction and she encouraged people to call to see if any last-minute slots become available.
Sarah added: 'We are fully booked but we are getting cancellations every day so it is worth giving us a call or a text, or going on to our Facebook page, and we will try to fit you in.'
Sarah also said that the centre would also be open as usual on December 28, 29 and 30.