The 64-year-old has been spotted enjoying the beach numerous times while working as a World Cup pundit for French television in South America.
One fan managed to grab a photo with the Frenchman while he relaxed on the beach, but once the image was posted on Twitter, the Gunners boss received some criticism for his choice of swimwear.
One user wrote: "There is a photo floating around of Wenger in speedos. It CANNOT be unseen," while another tweeted: "For the love of god, please can everyone stop posting pics of Arsene Wenger in his speedos in Brazil. In Arsene we trust NOT lust."
Former CNN television host Piers Morgan, who is an Arsenal fan, also mentioned Wenger's attire by tweeting: "Even his speedos are out-dated."