The 23-year-old moved to the Stadium of Light on an extendable season-long loan from ENPPI last summer.
The Black Cats have recently decided to turn Elmo's deal into a permanent transfer after he impressed in the Premier League over the past months.
The Egypt wing-back believes football fans in his homeland love to see Egyptian players ply their trade in Europe, and he's keen to live up to their expectations.
"I am very pleased for my fans in Egypt that Sunderland want me to stay permanently," Elmohamady told the club's official site.
"Not many Egyptian players play outside the country and it is good for them to see people playing in Europe.
"This is what they hope to see and it is very good for the game in Egypt."
Elmohamady and Borussia Dortmund's Mohamed Zidan are the only well-known Egyptian European-based footballers these days.