And Elphick's former management partner at Worthing, Jon Meeney, is coming in as first team coach.
Elphick, a popular member of the United squad already, steps up to take on the role vacated by Chris Agutter last week. Elphick will continue to be a member of the playing squad as well.
He will have the job of trying to lead Hastings United into the Isthmian premier division - after two unfinished seasons when they led the table but were denied by Covid-shortened campaigns.
He takes over a side who have stuttered recently, losing in the FA Cup, FA Trophy and league in recent weeks - although they remain well placed for a promotion charge.
The Hastings Observer was first to suggest last week that United may promote from within to replace Agutter.
Club chairman and CEO Billy Wood said there had been 97 applications for the job including some from bosses with experience at higher levels of the game than Hastings are at this season.
He said he was delighted to appoint Elphick and felt he, Brown and Meeney - a trio who have a huge amount of football experience between them - could take the club forward.
Their first game as a trio in charge is a big one -at home to Isthmian south east leaders Cray Valley PM on Saturday, likely to be in front of another 1,000-plus crowd.
Elphick said: “I’ve become very fond of Hastings United from my time as a player and I am looking forward to this opportunity of management again. I wish to continue from the good work Chris Agutter has done at the club in recent seasons.
"The foundations have been laid and it’s up to myself and the staff to get the best out of the players for progression to resume. Andrew Brown and the rest of the club staff will continue with their current roles, which is testament to them and shows the belief I have in them continue with the success we’ve had in recent seasons.
"I will continue playing this season, so I have bought Jon Meeney to the club to help assist Andrew Brown with training and matchday duties. Jon will be key and I’ve also experienced success with him at Worthing in a similar situation. He will add energy, knowledge and I look forward to working alongside him again.
"I like to thank Billy, Daren, and Peter for the opportunity, and I will do my upmost for the club. Lastly, I wish to mention the fans, my fondness for the club is mainly down to the rapport I have with the supporters. You’ve been first class with me, and I really hope I can achieve something special for you. Onwards and upwards! COYU.”
Wood said: "Gaz knows the club, knows what we are about on and off the pitch and with the addition of Jon Meeney it feels exciting and fresh. Gaz made it very clear how important Andrew Brown is to his vision and it’s something the club wholeheartedly agree with.
"We thank Browny for taking the team in the interim and whilst full faith was installed in him at this time, continuing in the role of Assistant Manager suits both the individual and the club perfectly. I urge the Us supporters to get behind the new management team. We all have a job to do, and I have full faith that we will get it done this season. Let’s pack the place on Saturday and get back to what we know best!”
Elphick started his playing career at Brighton, where he made two league appearances. He had loan spells with Eastbourne Borough - in September 2004 - and Aldershot Town, in January 2006.
In 2006 he was released by Brighton and signed for Conference side St Albans, and while there he played for the England National Game XI. He left for Havant & Waterlooville in 2007-08 where he quickly became a regular in the heart of the defence; then in 2009, he joined Eastbourne Borough.
It was on to Eastleigh in 2012 but he soon joined joined Tonbridge Angels. After a spell at Lewes, Elphick joined Worthing as joint manager with Jon Meeney in June 2015. He quit Worthing in 2017 after a poor start to the season and returned to being a player only, joining Burgess Hill. He moved to Hastings in 2019.