Platt, 19 and Thomson, 21, have both joined the National League outfit until the end of the season.
Both players played for Rovers' under-21 side this term in the EFL Trophy, but are yet to play a senior game.
Blackburn are currently 22nd in the second tier, while Barrow are seventh in the National League.
Barrow have signed defender Matty Platt and midfielder Connor Thomson on loan from Championship club Blackburn Rovers' development side.