The Egyptian international striker spent a season and a half with us after arriving on loan from the Italian side in January 2005.
He scored 11 goals in 27 appearances in the Premiership last term but a groin and then a knee injury ended his season a month early.
Martin Jol commented: We've been tracking Mido since his loan ended and we were always keen to bring him back.
Roma took some persuading and I'm delighted to have him in the squad.
He knows I like him as a player, his strength in the air and his mentality. It's an excellent addition to the squad and our striking options are now complete.
The 23-year-old has previously played for Zamalek, Gent, Ajax, Celta Vigo and Marseille.
I'm very happy to be back, said Mido at Spurs Lodge. It was and it always will be a great honour for me to play for Tottenham.
I always knew in my heart I would be coming back. It is a fantastic move for me, I have some good friends here and it will be good to be back with the lads. I saw them training today and I'm looking forward to working with Martin and Chris again.
I can't wait to pull on a Tottenham shirt, to play at the Lane and score some goals.
The Club is delighted to announce that we have reached agreement with Roma for the transfer of Mido, subject to the formality of receiving his work permit.