Increased banking and trading activity helped lift profits at JPMorgan Chase 17% from the same period in 2016, the bank said. Profits were $6.45bn (Â£5.1bn).
Citigroup's first-quarter profit also gained 17% to $4.1bn on revenue gains from institutional clients.
Citi's revenue was 3% up on 2016 to $18.1bn.
Both reports beat analyst expectations.
JP Morgan chief executive, Jamie Dimon, said the  background to the results was healthy: "US consumers and businesses are healthy overall and with pro-growth initiatives and improving collaboration between government and business, the US economy can continue to improve."
Chief executive, Michael Corbat, saw a similar picture: "The momentum we saw across many of our businesses towards the end of last year carried into the first quarter, resulting in significantly better overall performance than a year ago."
At JP Morgan, troubles at the consumer and community banking unit were offset by record revenues from commercial banking.
The firm's revenue increased to $24.7bn, up 6% from a year ago.
Provisions for credit losses fell 28% to $1.3bn. Last year, trouble in the oil and gas industry hurt results.
Separately Wells Fargo, which has been working to contain fallout from a scandal related to fake consumer accounts, said it earned $5.5bn in the first quarter, largely unchanged from a year ago.
Profits at two of the biggest US banks jumped in the first quarter, buoyed by higher interest rates.