Is the word tia the same in Brazilian and European Portuguese?

No

The spelling and primary meaning of the word "tia" (aunt) are the same in both Brazilian and Continental Portuguese. However, the difference lies in its typical usage.

In Brazil, "tia" is used much more broadly and colloquially. It is a common term of endearment or informal respect used to address or refer to older women who are not biologically related, such as family friends, neighbors, or even school staff and caregivers. In Portugal, the use of "tia" is much more restricted to biological or legal relatives. Calling a stranger or an acquaintance "tia" in Portugal would be considered unusual or overly familiar; instead, a Portuguese person would typically use "senhora" (ma'am/lady) to show polite respect.

Brazilian Portuguese examples:

1. "Oi, tia! Tudo bem?" (Hi, auntie! How are you?)
2. "A tia da escola é muito legal." (The school lady/auntie is very nice.)
3. "Aquela tia ali é minha vizinha." (That lady/auntie over there is my neighbor.)
4. "Minha tia mora no Rio." (My aunt lives in Rio.)
5. "Vou dar um presente para a tia." (I'm going to give a gift to auntie/the lady.)

Portuguese examples:

1. "Olá, senhora! Está bem?" (Hello, ma'am! Are you well?)
2. "A senhora da escola é muito simpática." (The lady from the school is very nice.)
3. "Aquela senhora ali é minha vizinha." (That lady over there is my neighbor.)
4. "A minha tia mora no Rio." (My aunt lives in Rio.)
5. "Vou dar um presente para a senhora." (I'm going to give a gift to the lady/ma'am.)