The former government minister was arrested in the economic capital Douala on January 28.
The prosecutor’s office of the Yaounde military court filed the charges against Kamto, who was transferred to a prison in the capital of Yaounde during the night, according to lawyer Emmanuel Simh.
Simh, who is also vice president of Kamto’s Movement for the Rebirth of Cameroon (MRC), said 28 of Kamto’s supporters were also charged.
About 100 others supporters are to appear on Wednesday before the military court, which will decide whether to charge them.
Kamto has said he was the rightful winner of presidential elections last October won by the West African country’s veteran leader Paul Biya.
Biya won a seventh consecutive term in the polls, which the MRC has slammed as an “electoral hold-up”.
Kamto won 14.23 percent of the vote to place second, according to the official figures.
MRC supporters turned out in several towns and cities on January 26 to dispute the official result. The demonstrations were suppressed by the police and at least six protesters were injured.
The MRC has said that around 200 people arrested during the protests are still being held in Yaounde.
Some of them, including MRC treasurer Alain Fogue, have launched hunger strikes.
The European Union has condemned Cameroon for the “disproportionate use of force” in dispersing the protests.
Biya has ruled the West African country since 1982 with support from the army, government administrations and the Cameroon People’s Democratic Movement (RDPC) that he created in 1985.