Millwall have confirmed the loan deal for the 18-year-old striker who has one cap with the Republic of Ireland.
Parrott signed a three and a half year contract with Spurs back in February, appearing in the first team time twice.
The Dubliner said he was buzzing with the deal and looking forward to experiencing the atmosphere at Millwall.
"I'm really grateful for the club letting me go and get some experience and some valuable game time. Hopefully I can improve a lot and get some game time at Millwall," said Parrott speaking to Millwall's official website.
A similar move was made by England captain Harry Kane, who went on loan to Millwall from Spurs in 2012, scoring nine goals for the club, a feat Parrott hopes to emulate.
“Harry chose Millwall and it was obviously the right decision for him at the time. Hopefully I can push on and buy into it for the season that I’m here."
