Kember said it was "great to be free" after he and two peace activist colleagues, Canadians Harmeet Singh Sooden and Jim Loney, were released Thursday.
Kember, 74, flew back to London after leaving Baghdad on a British military aircraft on Friday afternoon.
Canadians Sooden, 32, and Loney, 41, headed to Baghdad airport on Saturday to begin their journey home from Iraq, a colleague said.
Recently, some 150 members of the peace group Christian Peacemaker Teams gathered in central Toronto for their weekly prayers and to celebrate the rescue."It was a vigil we held weekly to grief. This week we combined our grief with celebrations," CPT co-director Doug Pritchard told AFP.
The three hostages were released after a pre-planned military operation involving British forces.
Tony Blair's spokesman said British forces took a "prominent" role in the rescue operation, but refused to comment further for fear of compromising any future hostage situations.
Foreign Secretary Jack Straw said: "The three hostages, Norman Kember, the British hostage, and two Canadians have been released as a result of a multinational forces operation which took place earlier [Thursday].
"It follows weeks and weeks of very careful work by our military and coalition personnel in Iraq and many civilians as well."
Mr Kember, from Pinner, Middlesex, had been in captivity with two Canadian hostages, James Loney, 41, and Harmeet Singh Sooden, 32, and an American Tom Fox, 54, since they were snatched in Baghdad on November 26.
The four were taken hostage by a mysterious group called the Swords of Righteousness Brigade. Mr Fox was killed in Baghdad by his captors on March 9. CPT announced a religious ceremony to be held in Toronto on April 2 in memory of Fox.
The four hostages travelled to Iraq last year as a "gesture of solidarity" with the Canada-based group Christian Peacemaker Teams (CPT).
