Yes, Wimbledon is one of the few major sporting events where you can buy premium tickets on the day of play – I have managed it three times. There are 500 Centre Court, Court 1 and Court 2 tickets available each day (except for Centre Court on the final four days).
When should I arrive?
You would have to camp for at least one night for the best chance of show court tickets. To give you a rough idea, in 2013 I arrived at the Queue (it has a capital Q where Wimbledon is concerned) at 2pm on Saturday for the second Monday and was 337th in line.