ThermophilicCampylobacterspecies are among the major etiologies of bacterial enteritis globally. This study aimed at assessing the antimicrobial resistance (AMR) profiles, virulence genes, and genetic diversity of thermophilicCampylobacterspecies isolated from a layer poultry farm in South Korea. One hundred fifty-three chicken feces were collected from two layer poultry farms in Gangneung, South Korea. TheCampylobacterspecies were isolated by cultural techniques, while PCR and sequencing were used for species confirmation. Antimicrobial susceptibility testing for six antimicrobials [ciprofloxacin (CIP), nalidixic acid (NAL), sitafloxacin (SIT), erythromycin (ERY), tetracycline (TET), and gentamicin (GEN)] was carried out by broth microdilution. Three AMR and nine virulence genes were screened by PCR. Genotyping was performed byflaA-restriction fragment length polymorphism (RFLP) and multilocus sequence typing (MLST). Of the 153 samples,Campylobacterspp. were detected in 55 (35.9%), withCampylobacter jejuniandCampylobacter colibeing 49 (89.1%) and six (10.9%), respectively. High-level resistance was observed for CIP (100%), NAL (100%), and TET (C. jejuni, 93.9%;C. coli: 83.3%). No resistance was observed for SIT. The missense mutation (C257T) ingyrA gene was confirmed by sequencing, while thetet(O) gene was similar to known sequences in GenBank. The rate of multidrug-resistant (MDR) strains was 8.2%, and they all belonged toC. jejuni. AllCampylobacterisolates possessed five virulence genes (cdtB,cstII,flaA,cadF, anddnaJ), but none possessedggt, while the rates for other genes (csrA,ciaB, andpldA) ranged between 33.3 and 95.9%. TheflaA-RFLP yielded 26flaA types (C. jejuni: 21 andC. coli: five), while the MLST showed 10 sequence types (STs) forC. jejuniand three STs forC. coli, with CC-607 (STs 3611) and CC-460 (ST-460) being predominant. Among the 10 STs ofC. jejuni, three were newly assigned. The findings of this study highlight the increased resistance to quinolones and TET, the virulence potential, and the diverse genotypes amongCampylobacterstrains isolated from the layer poultry farm.