This study presents whole-rock major, trace elements and Sr-Nd-Hf isotopic compositions, as well as zircon U-Pb geochronological data, for the peraluminous and aluminous granitoids in northern Guangdong Province, South China, in order to investigate their petrogenesis and tectonic implications. The Qingzhou granodiorites (458.5–455.4 Ma) are peraluminous (A/CNK = 1.05–1.96). They have relatively high initial 87Sr/86Sr ratios (ISr = 0.7087–0.7148), low εNd(t) values (?11.2 to ?10.1) and a variety of zircon εHf(t) values in the range ?13.4 to +4.81. By contrast, the Damaoshan granodiorites (458.1 Ma) are metaluminous (A/CNK = 0.79–0.94) in composition, with ISr values of 0.7083 to 0.7110, εNd(t) values of ?7.92 to ?5.28 and zircon εHf(t) values of ?8.69 to ?2.06. The Gaoshou quartz diorites (449 Ma) are metaluminous-peraluminous. Their ISr values vary from 0.7104 to 0.7111 with εNd(t) values from ?9.64 to ?8.63. Geochemical data and Sr-Nd-Hf isotope compositions indicate that the Qingzhou, Damaoshan and Gaoshou intrusions are primarily derived from the partial melting of metagreywackes, tonalitic rocks and amphibolite, respectively. The crustal materials in northern Guangdong, from top to bottom, consist of Paleozoic sequences, metasediments with a Vp of < 6.0 km/s, metaigneous rocks with a Vp of 6.3–6.7 km/s and amphibolite with a Vp of ~7.03 km/s.