"It is the domination of space, this is an act ... of independence.
"Now we have a socialist satellite to construct socialism in Venezuela and co-operate with others, which is why the satellite Simon Bolivar was created. Congratulations."
He said the project would break the mould of "technological illiteracy."
Designed to offer radio, television and internet in three band frequencies, the satellite has joined nearly 3,000 others orbiting the earth.
The signal from the Simon Bolivar - expected to be fully operational by January - will extend from southern Mexico to southern Argentina and Chile.
"I think this telecommunications satellite is a human right for the nations of South America and the Caribbean"
Evo Morales, president of Bolivia
A senior Venezuelan military official said the satellite was for peaceful purposes and would not be used for spying.
The satellite, with a lifespan of 15 years, will orbit the Earth at 36,000km.
Venezuela paid around $241m for the satellite, along with another $165m for two communication headquarters.
The main technical base, in El Sombrero, is only a few hours from Caracas, Venezuela's capital.
Chavez had rejected calls from Washington for China to suspend the launch, and described the move as part of Washington's "obsession to conquer the world".
"The Chinese government's response was that there was no reason to suspend the launch," he said.
Morales congratulated Chavez, saying: "I think this telecommunications satellite is a human right for the nations of South America and the Caribbean, and should not [be] a private enterprise."
The Simon Bolivar was manufactured in, and launched from, China as part of a 2002 technological co-operation agreement between the governments.
Venezuela intends to launch a second satellite in 2013, according to Rodolfo Navarro, the technical manager of the Bolivarian Agency for Space Activities.