The 21-year-old Spain international, who had been linked with a move to Barcelona where he started his career, arrived in London in 2011 and has established himself as Arsenal's first-choice right back.
"I'm really, really happy and this club is my home right now," Bellerin told the club website.
"I wasn't thinking about anything else other than staying here and continuing my development here," he added.
"Arsenal is not only about being a footballer, you have to be a good person to play here. That's what everyone transmits inside the club."
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British media reported that Bellerin had extended his contract with Arsenal to 2022.
(Reporting by Ed Osmond; editing by Martyn Herman)
