The order will be in place until 6.59pm on Friday.
It covers a large area, including Above Bar Street, West Quay Retail Park, East Park, Hoglands Park, and Watts Park.
The order aims to prevent potential harassment, alarm, or distress caused by individuals at the location.
Officers will be able to order individuals known for, or suspected of, causing such disturbances to leave the area for a specified period.
Returning to the designated area after being directed to leave is considered a criminal offence, which can lead to an arrest.
Southampton City Centre dispersal order area (Image: Hampshire Constabulary)
A spokesperson for Hampshire police said: “A dispersal order has been authorised in the city centre and will remain in place until 6.59pm tomorrow.
“This follows recent reports of anti‑social behaviour and instances of aggressive and persistent begging.
“These powers allow officers to direct individuals to leave the designated zone if their behaviour is causing, or is likely to cause, harassment, alarm or distress to others.
“Anyone who refuses to comply may commit a criminal offence and could be arrested.”
Police declined to give further detail about the reasons behind the dispersal order.