The British singer announced the news that his romance with Eleanor Calder is over after photographs emerged of him kissing a mystery brunette while on holiday in Thailand.
A representative for Tomlinson tells People magazine, "Louis and Eleanor split up two weeks ago. They have not announced this as they wanted some privacy during this time."
A source adds, "Louis is really upset about it all. They tried really hard to make it work but it was just impossible, he's away for nine months a year and they just grew apart."
The pair dated for almost four years after meeting in 2011.
The news comes days after Tomlinson's One Direction bandmate Zayn Malik was signed off with stress following a storm of publicity after he was pictured apparently holding hands with a young woman in Thailand.