Can I Extend a 30 Day Visa Exempt Entry in Thailand Without Leaving?

and we see how again the misuse of terminology throws answers off the rails.

There is NO such thing as a 30 day tourist visa, and as it was pointed out IF you as an Aussie passport holder winged your way here without having bought a visa from a thai consulate before hand and were stamped in for FREE for 30 days you got in on what's called a 30 day visa exempt entry.

You CAN apply for a 30 day extension on that at the immigration office in the area where you stay for 1900baht.

In Bangkok that is out at the government complex on Chaengwattana Road, Building B, second floor, south entrance.

If you mean that you came to Thailand without any visa and got a 30 day Admitted to Stay you might be able to apply for a 30 day Extension of Stay at your local immigration Office.

Most offices you can directly apply, Pattaya immigration only allows ou to apply during the last few days of your admitted to stay period

No, 30 day tourist visa on arrival do not exist in Thailand,