Raila eulogised his close friend as a source of inspiration to many.
Tsavingirai passed away on Wednesday after battling against colon cancer in South Africa aged 65 years.
Odinga said he learnt of Tsvangirai passing with deep sorrow and eulogized the Zimbabwean opposition leader as a man who dared to dream of democracy, freedom and justice for his country and his people despite the firm hands of dictatorship that held sway.
Odinga, a former Prime Minister himself, said Tsvangirai remained a source of inspiration to a generation of leaders across the continent for his courage in the face of monumental odds.
“His death leaves a gap in a country that still needs strong forces of change to return to the path of democracy. I pray that the party he founded, the MDC, will hold firm and pursue the ideals he lived for. My family, our party the Orange Democratic Movement and the National Super Alliance join Mr. Tsvangirai’s family, the MDC and the people of Zimbabwe in mourning his death,” Odinga said on his Twitter account.
Odinga’s close relationship Tsavingirai was brought to the fore in 2012 when the late Zimbabwean leader was the chief guest at the Orange Democratic Movement (ODM) National Delegates Conference where the NASA leader was endorsed as the party's presidential candidate.
The NASA leader had himself months before attended a Movement for Democratic Change (MDC) meeting in Zimbabwe that showed the close ties the two leaders shared.
In 2008, Odinga called on African leaders to push Mugabe out of power terming him as a stumbling block to political reform in Zimbabwe.