The move comes after the Zaire native had spent seven-plus years with the Seagulls, totalling 183 appearances for the club while scoring 22 goals.
Hughton talks about LuaLua departure
Speaking about the now-former Seagull, Brighton boss Chris Hughton said: “The competition for places in our wide areas means that it has been very difficult for Kazenga to play the number of matches he would have liked here.
“He has worked tremendously hard during his time with us and has played a major part in the club’s history. I would like to wish him all the very best for the future on behalf of everyone at the club.”
Coleman speaks about LuaLua arrival
In joining the Black Cats, LuaLua will find himself with a squad that is currently 22nd in the Championship table, having spent the majority of the season in the bottom three.
Sunderland manager Chris Coleman spoke to the club's official website on LuaLua joining the club: "Kaz was determined to come here and get playing first-team football again and I look forward to helping him play the kind of football he is capable of."
The former Wales boss added: "He’s quick, skilful and has a lot of experience at this level.
"He gives us another option in attack and, most importantly, is up for the fight.”
LuaLua comments on joining Black Cats
Upon linking up with his new club, LuaLua said "it's nice to be back. I know the area," while also adding that he "kept himself in good physical shape" during his time on the sidelines.
The 27-year-old added: "I've played many games in the Championship before. it's such a tough league", and LuaLua feels that "with the experience I have, I can always learn from them (his new teammates), as well".