Thomas Cook will stop selling trips to animal parks where killer whales are kept captive, such as SeaWorld and Loro Parque.
The travel provider’s decision was prompted by customer feedback, with more than 90% saying it was “important” that their holiday company took animal welfare seriously.
Evidence from animal welfare specialists also played a part in the decision, according to Thomas Cook chief executive Peter Fankhauser.
He wrote in a blog post: “This was not a decision we took lightly.
“We have actively engaged with a range of animal welfare specialists in the last 18 months, and taken account of the scientific evidence they have provided.”
Thomas Cook announced a new animal welfare policy around 18 months ago and, soon afterwards, 29 attractions were removed in a audit.
SeaWorld and Loro Parque, in Tenerife, had passed the audit process but will now also be struck off the list, the firm said.
The move will take effect from next summer.
At least 40 orcas and dozens of dolphins have died at SeaWorld parks from causes including severe trauma, intestinal gangrene and chronic cardiovascular failure, according to PETA.
The animal rights organisation has been putting increasing pressure on Thomas Cook to sever ties with SeaWorld in recent years.
Mr Frankauser said: “We respect and applaud the work that has been done, and we will work with both over the next 12 months to prepare for our exit.
“We will also continue to work ourselves to identify more sustainable alternatives.”
In 2013, the documentary Blackfish sparked a public backlash after it shone a light on the lives of killer whales in captivity.
The film concerns a captive orca named Tilikum who was involved in the deaths of three individuals.
It also looks at the consequences of keeping orcas in captivity.
SeaWorld described the documentary as “inaccurate and misleading” and it subsequently suffered a $15.9m (£12.1m) loss, which then chief executive James Atchison attributed in part to the weather.