Mido was at the club on loan for 18 months since January 2005.
A groin followed by a knee injury meant the Egyptian missed the last month of the season but he had scored 11 goals in 27 Premiership appearances prior to that.
Martin Jol said: "We've been tracking Mido since his loan ended (in May) and we were always keen to bring him back. Roma took some persuading."
"It's an excellent addition to the squad and our striking options are completed."
Mido said: "I always knew in my heart I would come back. I saw the lads training today which was good."
Source: TottenhamHotspur.com