Four caravans were reported at the Go Outdoors site on Third Avenue, Millbrook Road, on Friday, March 20, after arriving at around 1pm.
A member of staff at the store said police had attended the site shortly after the group arrived, adding that some of the travellers had entered the shop.
The staff member said those at the encampment indicated they did not expect others to join them and planned to leave after the weekend.
Go Outdoors car park in Millbrook, Southampton. (Image: Cristiano Magaglio)
Southampton City Council confirmed it had been made aware of the situation, although the land is privately owned.
A spokesperson previously said: “Whilst the land is not owned by the council we will liaise with the landowner and make the appropriate welfare checks.”
By Sunday, March 22, the group had left the site. It is not clear when they departed.