The 19-year-old is yet to make his first-team debut for the Championship side but recently enjoyed a successful loan stint with Skrill South outfit Tonbridge Angels.
Goodwin is available to make his Gulls bow in new boss Chris Hargreaves' first match in charge at AFC Wimbledon on Saturday.
Brighton head of football operations David Burke said, "After his successful loan spell at Tonbridge, Shamir now has the opportunity to showcase his abilities in the Football League.
"He will need to adapt because he is entering a higher level but, as with all loan spells, the move is there to help the growth of the player and it adds to the experience he already had earlier this season."
- Sports & Recreation
- Tonbridge Angels
- Chris Hargreaves
- AFC Wimbledon