The deal will see the 28-year-old central defender rack up a decade of service at the club, earning him the right to a testimonial year.
El-Abd hooked up with the rest of the squad this morning for his first day of pre-season training, and is likely to feature in Saturday’s curtain-raiser at Whitehawk.
He told seagulls.co.uk, “I'm absolutely delighted to have signed the new deal. I love playing for the club, and I can't wait for the season to start now.
“I've been keeping myself fit in the gym, and although it's not the same as doing pre-season, I feel really good and I'll definitely be fit for the start of the season.
“The last ten years have been amazing, and I feel really honoured to have been granted a testimonial year by the club.”
Head of football operations David Burke added, “It is fantastic news that Adam is staying with us and he will reach the milestone of ten years at the club which is a fantastic achievement.
“Adam has played a major part in getting the club to where it is today, and we are delighted that he has chosen to commit to the club for longer.
“He is a product of the club’s successful youth system and is somebody all our younger players should aspire to.”
One of the club’s most consistent defenders over the last decade, Brighton-born El-Abd played a crucial part in the League One title success in 2011, and in May 2012 he was called up to the Egypt international squad.
He has made over 250 appearances for the club since he was handed his first team debut in 2003 by Mark McGhee.