Inclusion Criteria:
* Participants who have definite diagnosis of active psoriatic arthritis (PsA) (according to the ClASsification criteria for Psoriatic Arthritis \[CASPAR\]) prior to the first administration of study drug and have at least 1 of the PsA subsets: distal interphalangeal joint arthritis, polyarticular arthritis with the absence of rheumatoid nodules, arthritis mutilans, asymmetric peripheral arthritis, or spondylitis with peripheral arthritis
* Participants who are negative for rheumatoid factors
* Participants having inadequate response (defined by presence of active arthritis \[presence of any swollen or any tender joint\]) to standard therapies for 3 months at the highest recommended dose (e.g., conventional disease-modifying antirheumatic drugs \[DMARDs\] including methotrexate, apremilast, or nonsteroidal anti-inflammatory drugs \[NSAIDs\]), including biologics naïve patient or have failed, or were intolerant to one or more biological treatments \[anti-TNF/IL-17i\]
* Participants are considered eligible per the following Tuberculosis (TB) screening criteria:
1. Have no history of TB prior to screening AND
2. Have no signs or symptoms suggestive of active TB upon medical history and/or physical examination AND
3. Have had no recent close contact with a person with active TB, or if there has been such contact, will be referred to a physician specializing in TB to undergo additional evaluation and, if warranted, receive appropriate treatment for latent TB prior to or simultaneously with the first administration of study drug AND
4. Within 6 weeks prior to the first administration of study drug, have a negative QuantiFERON- TB Gold and a negative tuberculin skin test result, OR have a newly identified positive QuantiFERON-TB Gold or tuberculin skin test result during screening in which active TB has been ruled out and for which appropriate treatment for latent TB has been initiated either prior to or simultaneously with the first administration of study drug AND
5. Have a chest radiograph (both posterior-anterior and lateral views), taken within 3 months prior to the first administration of study drug and read by a qualified radiologist, with no evidence of current active TB or old inactive TB
* Medically stable on the basis of physical examination, medical history, vital signs, and 12-lead ECG
* A woman of childbearing potential must have a negative highly sensitive serum beta-hCG at screening visit
Exclusion Criteria:
* History of latent or active granulomatous infection prior to screening
* Have a known clinically significant hypersensitivity to guselkumab or to any of the excipients
* Have had a serious infection, or have been hospitalized for an infection, or have been treated with intravenous (IV) antibiotics for an infection within 2 months prior to first administration of study intervention
* Has any known malignancy or has a history of malignancy, or a history of lymphoproliferative disease
* Have received, or are expected to receive, any live virus or bacterial vaccination within 3 months before the first administration of study intervention, during the study, or within 6 months after the last administration of study intervention
