Elphick, 31, has put pen-to-paper on a two-year contract running until 30 June 2021.
The defender explained why he thought Huddersfield Town was the perfect side for him.
“Watching from the outset from the last three years, the connection the players have with the fans, the team spirit the Club has been renowned for and the recent success that the Club has had, it's a good challenge for me at this stage of my career.
“First of all, we need to restore that confidence, get back to winning ways and get back into that habit.
“I believe with the playing squad and the staff we've got we can have an enjoyable and successful year.
“I will promise that I'll give everything and try to get us back to the top end of the table, winning games, getting smiles back on fans' faces and having that connection.
“Something I've prided myself on is not leaving anything behind and I'm certain I'm not going to do that now."