|Character of Upin & Ipin|
| Nur Fathiah Diaz (season 1-3)|
Asyiela Putri (season 4-now)
Despite Upin and Ipin are twin agreeable brothers and are bald-headed together, Upin is different from Ipin because of Upin's hair that stands out on his bald hair and often wears a yellow singlet that is printed with the letter "U".
Upin talks a lot in the series. As a older brother, Upin shows leadership to Ipin, and more find a way and plans for his brother than otherwise. When not being naughty, Upin also corrects the mistakes of his brother. Upin and Ipin are rarely far apart, indicating that they need each other.
|Upin | Ipin | Ros | Opah | Tok Dalang | Mei Mei | Jarjit | Ehsan | Fizi | Mail | Susanti | Dzul | Ijat | Devi | Jasmin | Muthu | Salleh | Rembo | Ah Tong | Sapy | Apin | Rajoo | Oopet | Pak Mail | Singh | Nurul | Nurul binti Ahmad | Tiger | Melati | Hamzah|