The forward made his name with the Seagulls at the start of his career and went on to play for Tottenham, West Ham, Fulham and QPR, winning a pair of England caps during his Fulham days.
He first joined Brighton in the summer of 2000 and helped them to back-to-back promotions in 2001 and 2002 before moving on to Spurs.
And he completed a medical at the American Express Elite Football Performance Centre on Monday evening before signing the paperwork which sealed his return to the Seagulls.
Brighton boss Chris Hughton said: “We are absolutely delighted to have brought Bobby back to Brighton, he needs absolutely no introduction here.
“The Albion fans know everything about him, from his achievements in a Brighton shirt and right through his time with Spurs, West Ham, Fulham and QPR.
“I also know Bobby well, having worked with him during his time at Spurs, and he is a great professional.
“I know he will bring plenty of experience to the team, having played Premier League, European and international football.
“He will also bring a lot in terms of character to the club and to the dressing room but, most importantly, having played more than 30 times for QPR last season, he brings top quality to our offensive options.
“We still have work to do in terms of adding to the squad, including those offensive options, in terms of creating and scoring goals.”
Zamora helped Fulham to reach the Europa League final in 2010 but an injury ruled him out of the World Cup finals that year.
During his subsequent spell at QPR the 34-year-old scored a dramatic late winner against Derby in the 2014 Championship play-off final but the west London club were relegated straight back down last season and Zamora departed at the end of the campaign.
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