The media company said Christian Woolfenden will join next month with Anne Marie Cannon following on November 1.
Mr Woolfenden is currently a marketing executive at bookmaker Paddy Power. Prior to that he held senior international marketing roles at drinks giant Bacardi and consumer goods conglomerate Proctor & Gamble.
STV said he will replace Vasa Babic who stepped down last month after seven years on the board.
Ms Cannon has accumulated more than three decades of experience in investment banking and the energy industry. Her career includes roles at Shell UK, J Henry Schroder Wagg, Hardy Oil and Gas and Morgan Stanley.
She has served on the board of Aker and is currently a non-executive director at Premier Oil and deputy chair at Det Norske Oljeselskap.
STV chairman Margaret Ford said of the appointments: I am delighted Christian and Anne Marie will join the STV Board. Both will bring insight and new perspectives to STV as we embark on the next phase of the growth strategy. I look forward to working with both of them in due course as we continue to create value for shareholders."
STV is launching its new television channel for Glasgow at the start of next month.
A seperate service for Edinburgh pencilled in to begin broadcasting in December.
In addition, the company has also recently overhauled its branding and that will be unveiled alongside the new channel.