The 19-year-old midfielder captained Albion’s under-23s last season and made an appearance as a substitute in the 2-0 win over Preston North End last September in the Carabao Cup - his second appearance in the competition after he made his first-team debut against Aston Villa in September 2019.
Aberdeen finished fourth in the Scottish Premiership last season.
'A great opportunity'
The Seagulls' technical director Dan Ashworth said, “This is a great opportunity for Teddy to take the next step in his development.
“This is the opportunity he needs to play regular first-team football. The Scottish Premiership is probably the strongest it has been for years next season with big clubs like Hearts and Dundee promoted.
“Aberdeen are also in the new Europa Conference League and I’m sure Teddy will relish the challenge of playing regular first-team football.
“We wish him every success and of course we’ll be monitoring his progress carefully during the season.”
The athletic, high energy player, who is highly thought of, has also featured for his country at Under 16 and 17 level.
And Aberdeen boss Stephen Glass believes the Club is fortunate to be adding a young talent of Teddy’s ability to the squad.
'A good pedigree'
“We are very pleased to be able to add Teddy to the group. The Club has had great success with loans of this nature, and we are confident this one will be the same," he told the club's website.
“Teddy comes with a good pedigree; he has played youth internationals for England and has made his debut for the Brighton first team.
“He is a good all-round central midfield player, and he will provide good competition in that area of the pitch.
“We are confident this move will help both Teddy’s career and our campaign this season.”