Buchtmann joined Liverpool in 2008 from Borussia Dortmund and played a key part in helping Liverpool Under-18s reach the FA Youth Cup final in 2008-09.
The 17-year-old, who can play at left-back or in midfield, has signed an 18-month contract at Craven Cottage.
Loan deal: Shorey joined Fulham earlier today
Buchtmann was named among UEFA's top 10 stars of the future in May 2009and also featured for Germany when they won the UEFA Under-17 EuropeanChampionship last year.
Fulham manager Roy Hodgson signed left-back Nicky Shorey on loanfrom Aston Villa earlier today and now has adequate cover for PaulKonchesky, who is out with a foot injury.
Hodgson also signed Roma striker Stefano Okaka today and allowed Diomansy Kamara to join Celtic on loan.
Meanwhile Wayne Brown has joined Coca-Cola League One side Bristol Rovers on a one-month loan deal.
Brown, 21, had a loan spell with Finnish side Turun Palloseura lastseason and will hope to get more first-team experience under his beltat the Memorial Stadium.
The Fulham academy graduate goes straight into Paul Trollope's squadfor the Pirates' match against Leyton Orient at Brisbane Road onTuesday night.
TRANSFER DEADLINE DAY LIVE: Robbie Keane in talks with Celtic, Johnson completes Man City switch and West Ham sign Mido and McCarthy - all the deals and drama as they happenKamara leaves Fulham for Celtic as Hoops also pick up Motherwell's SlaneNew Fulham loan signing Okaka eyes long-term stay at Craven Cottage Shorey joins Fulham on loan with view to permanent switch from Aston Villa FULHAM FC