Brown, 28, who first joined Sussex as an 11-year-old, led the side last season when Luke Wright, his predecessor, was injured and is stepping up from his role as vice-captain.
Ben said: “For someone who has been associated with Sussex for so long being appointed as captain is a very proud moment for me.
“I enjoyed the challenge of captaining the side last season but I feel in the last 12 months that the team has grown with a good core of senior players. Of course, I have my own ideas about how I want to lead the side but I also know there are some very solid cricketers in our dressing room who can give me support and advice if I need it.
“It’s an exciting time. We have eight Championship games left but we go into Monday’s match against Gloucestershire with some real momentum. If we keep playing as we have in recent weeks the table will take care of itself and we can challenge for promotion.”
Head Coach Mark Davis added: “As our vice-captain and a key senior member of the team we’re delighted Ben has agreed to take over as skipper. He learned a lot last season when he led the side when Luke Wright was injured and he will be a better captain for that experience.
“He will do the job for the rest of the season when the cricket management team will review the situation. We have no plans to appoint a vice-captain because we feel there is already a good group of senior players in our squad who can support Ben.
“I’m sure everyone involved in Sussex cricket will get behind Ben for the remaining eight Championship games, starting on Monday against Gloucestershire. He’s been a popular member of the Sussex family for many years and we’re sure this is a challenge he will absolutely relish.
“I’d also like to say a big thank-you to Chris Nash who led us to victories in his two games in charge against Worcestershire and Leicestershire. I’m looking forward to Nashy making a big contribution in the rest of the season as a senior player and a key batsman in the side.”
The club have also named Ross Taylor will lead Sussex Sharks in this year’s NatWest T20 Blast competition, which starts against Glamorgan at Arundel Castle on July 9th.
Taylor, 33, has vast captaincy experience from his lengthy international career with New Zealand. He has played 63 T20 internationals and last year he scored more than 400 runs for the Sharks in the NatWest T20 Blast.
Ross said: “I am very proud to be appointed captain of the Sharks for this season’s competition. I know the club and the players well from my time at The 1st Central County Ground, Hove in 2016 and I am looking forward to joining up with the boys again.
“I believe we have a very exciting squad for this format and one that can challenge any team in the competition.”
Sussex’s NatWest T20 Blast season ticket are still available through the Sussex Cricket website (www.sussexcricket.co.uk/tickets), or in person within the club shop from as little as £105. Buy your season ticket today and join the Sussex Family to show your support for Ross and the rest of the Sussex CCC squad.