The present study aimed to estimate the heritabilities of behavioral, growth, carcass, and growth curve traits and to determine the genetic and phenotypic relationships among these traits in Japanese quail (Coturnix japonica). A total of 500 quail chicks originating from a pedigree population were evaluated for growth performance, carcass characteristics, growth curve parameters, and behavioral traits. Genetic parameters were estimated using multi-trait animal models based on pedigree information. Heritability estimates for body weight traits ranged from 0.19 to 0.71, indicating substantial additive genetic variation for growth performance. Feed conversion ratio traits showed low to moderate heritability estimates (0.06–0.45), whereas growth curve parameters exhibited heritabilities ranging from 0.13 to 0.44. Among behavioral traits, feather pecking (0.35), wing stretching (0.30), and aggressive pecking (0.28) displayed the highest heritability estimates. Favorable genetic and phenotypic relationships were observed between feeding and inactivity behaviors and growth and carcass traits, while walking behavior showed moderate negative genetic associations with BW42. In contrast, welfare-related behavioral traits generally exhibited weak relationships with production traits. Genetic correlations among several behavioral traits suggested the existence of common biological mechanisms influencing behavioral expression. These findings demonstrated that behavioral traits possess exploitable genetic variation and should be considered alongside conventional production traits in future poultry breeding programs aimed at improving both productivity and animal welfare.