Yes, Hastings Kamuzu Banda (1898–1997) was unequivocally Malawian, and he spoke his native language fluently. Claims to the contrary are false.
Banda led Malawi to independence (1964) and ruled as President (1966–1994). His regime promoted Chichewa as the national language (alongside English), used it in speeches, radio broadcasts, and education. His fluency was never in question domestically.
Myths may stem from his long absence abroad (studied in US, practiced medicine in UK/Ghana 1940s–1958), his authoritarian rule (critics may have spread disinformation), or confusion with other leaders. But historical records, speeches, and contemporaries confirm his Malawian identity and linguistic competence.
Bottom line: Banda was Malawian by birth, ethnicity, language, and political career. The claim he wasn't—or didn't know Chichewa—is baseless.