Two new species, Lecanora hafelliana L. Lü, Y. Joshi & Hur and L. loekoesii Y. Joshi, L. Lü & Hur, are described as new to science from South Korea and eight species, L. campestris (Schaer.) Hue, L. cenisia Ach., L. nipponica H. Miyaw., L. perplexa Brodo, L. plumosa Müll. Arg., L. polytropa (Hoffm.) Rabenh., L. subrugosa Nyl. and L. sulcata (Hue) H. Miyaw., are recorded from South Korea for the first time. Lecanora hafelliana is characterized by the presence of hafellic acid, which is reported for the first time in this genus, while L. loekoesii is characterized by multispored asci and a thallus containing norstictic acid.