Fines issued by the UK's' Gambling Commission rose from £1.6 million to £18 million for the year ending 1 April 2018.
The rise was linked to a crackdown on money laundering and unfair practises.
The Commission's new enforcement report published on Thursday summarises investigations and best practice, asking gambling chiefs to “lead a culture of compliance”.
William Hill received a fine of £6.2 million in February for breaching anti-money laundering regulations and social responsibility policies. Just last week, 32Red were also fined £2 million for fail to protect online gamblers.