A Study of Guselkumab in Pediatric Participants With Moderately to Severely Active Crohn's Disease

Inclusion Criteria: * Participants must have a diagnosis of Crohn's Disease (CD) or fistulizing CD, with active colitis, ileitis, or ileocolitis, confirmed at any time in the past by clinical, endoscopic, and histologic criteria. * Participants must have moderately to severely active CD (as defined by a baseline Pediatric Crohn's Disease Activity Index \[PCDAI\] score greater than or equal to \[\>=\] 30) * Participants must have endoscopy with evidence of active CD defined as Simple Endoscopic Score for Crohn's Disease (SES-CD) score greater than or equal to (\>=) 6 (or \>=4 for participants with isolated ileal disease) within 1 month of receiving study intervention at Week 0 * Participants must have a history of inadequate response, loss of response, or intolerance to immunomodulators (6-MP, AZA, or MTX), oral or IV corticosteroids, or biologic therapy/JAK inhibitor therapy; OR have a history of corticosteroid dependence; OR have a history of inadequate response to exclusive enteral nutrition (EEN) Exclusion Criteria: * Participants has complications of CD such as symptomatic strictures or stenosis, short gut syndrome, or any other manifestation that might be anticipated to require surgery. * Participants must not have an abscess * Participants must not have any kind of bowel resection within 26 weeks or any other intra-abdominal surgery within 12 weeks of baseline