JP Morgan and Evercore ISI were lead underwriters.
Aside from the underwriters, investors bought $113.75 million worth of shares priced at $65 each.
Piedmont will use the funds to restart operations at North American Lithium in Quebec - where it has a 37% interest - as well as fund exploration and feasibility studies on its other assets in North America and Ghana.
The cost to restart is yet to be defined.
Piedmont plans to develop 60,000t per annum of lithium hydroxide capacity in the US, and produce more than 500,000tpa of lithium spodumene from multiple hard rock mines, including one in Ghana.
Piedmont had cash of $64 million at the end of December.
Equities in Piedmont were up 9% to A$1.01 in Australian trade, capitalising the company at $1.6 billion. Piedmont's equities on the ASX are CDIs, with one Piedmont share on NASDAQ equivalent to 100 CDIs.
