Tony Lloyd, the MP for Rochdale, follows Lesley Laird in the shadow cabinet role after she lost her seat in last week's general election.
Mr Lloyd will keep his current role as shadow Northern Ireland secretary.
Labour lost all but one of its Scottish MPs in the election, with only Ian Murray retaining his Edinburgh South constituency. Mr Murray served as shadow Scotland Secretary for a year but resigned in protest at Jeremy Corbyn's leadership following the EU referendum in 2016.
Until Ms Laird's election in 2017, the MP for Blaydon in northeast England, Dave Anderson, also served both as shadow Scotland and shadow Northern Ireland Secretary.