The new deal will keep the 29-year-old centre-half at White Hart Lane until the summer of 2016.
Dawson joined Tottenham from Nottingham Forest in January 2005, in a join £8million deal with Andy Reid.
The England centre-back has made 293 appearances and scored 10 goals for the club.
Dawson came close to joining Queens Park Rangers in August 2012 after Andre Villas-Boas took over as Spurs boss.
