The jobless rate rose to 5.2 per cent in May, ending a streak of eight months of job gains.
T-D director of economics James Orlando says the question now is whether this is a one-off, or the start of a trend.
Overall, employment was little changed last month as the economy lost a modest 17-thousand jobs.
Earlier this week, the Bank of Canada raised its key interest rate by a quarter of a percentage point to 4.75 per cent.
The move was in response to a string of hot economic data, including a surprisingly resilient labour market.