Hillary Rodham Clinton and her husband made at least $30 million over the last 16 months, mainly from giving paid speeches to corporations, banks and other organizations, according to financial disclosure forms filed with federal elections officials on Friday.

The sum, which makes Mrs. Clinton among the wealthiest of the 2016 presidential candidates, could create challenges for the former secretary of state as she tries to cast herself as a champion of everyday Americans in an era of income inequality.

The $25 million in speaking fees since the beginning of last year continue a lucrative trend for the Clintons: They have now earned more than $125 million on the circuit since leaving the White House in 2001.

In addition, the report shows, Mrs. Clinton reported income exceeding $5 million from her memoir of her time as secretary of state, “Hard Choices.”