The bank says 57 per cent of about 300 business owners contacted for the study said they use social media.
That's up 17 points from 40 per cent in last year's study.
BMO's report is based on a Pollara telephone survey of 301 business owners, conducted between Aug. 22 and Sept. 10.
Nearly 40 per cent of the respondents said they use social media to seek ideas or suggestions
About one-third said they track what's being said about their business and one-quarter check out feedback about their competitors.
About 25 per cent said they were using social media to search for new talent, up 11 percentage points from last year.
BMO's study found Facebook was used by 43 per cent of respondents, while LinkedIn was used by 23 per cent and Twitter by 11 per cent.