Irritability is a transdiagnostic symptom in oppositional defiant disorder, depression, and anxiety, all highly comorbid disorders but with unknown simultaneous evolution. The aim was to obtain the developmental trajectories of simultaneous irritability and oppositional, depression, and anxiety problems from preschool age to early adolescence. A sample of 493 community children was followed up annually from ages 3-11 years and assessed using categorical and dimensional measures answered by parents and teachers. Latent Class Growth Analysis for four parallel processes was used to identify distinct groups of individual trajectories for irritability and oppositional, depression, and anxiety problems. Outcomes at ages 11 and 12 were compared among trajectories using regression models and multiple comparisons. A 3-class model showed the highest entropy (0.961) and adequate posterior probabilities of class membership (≥0.969). Class 1 (n = 331, 67.1%) was made up of children with stable low scores in all the variables; class 2 (n = 55, 11.2%) of children with high depression, anxiety, and irritability and above the mean stable profiles for oppositional problems; and class 3 (n = 107, 21.7%) of children with medium-high increasing irritability and oppositional problems and on the mean depression and anxiety. The classes with symptomatology and irritability (2 and 3) clearly differed from class 1 (low) at baseline and in outcomes. The course of irritability and oppositional, depression, and anxiety problems from ages 3-11 years differed qualitatively and quantitatively across subgroups of children. The 3 classes identified may help to guide clinicians' decision-making regarding treating irritability and its comorbid disorders.