The 26-year-old makes the temporary switch from the Bees after a year-and-a-half at the club in search of consistent game time.
Goode arrived in West London in August 2020 after leading Northampton to promotion to League One via the play-offs in 2019/20, helping keep a clean sheet in a 4-0 win against Exeter in an empty Wembley Stadium.
He has gone on to make 20 appearances for the Bees, including six in the Premier League this season, but has been unable to break the duopoly of Pontus Jansson and Ethan Pinnock, as well as falling behind Kristoffer Ajer in the pecking order.
The centre-back moves to Yorkshire with the Blades sitting 11th in the Championship, six points outside the play-off spots and with at least two games in hand.
He has described them as a 'massive club' and is excited for the opportunity. He outlined his decision to join Sheffield United to the club's media.
"I'm a player that's desperate to play. I love playing week in, week out, and I wanted to come here and be a part of it.
"I've been watching from the outside in recent weeks and, with the games in hand and where they're positioned in the league, there's no reason why we can't fly up that league and I want to part a part of that. "
Goode has had a meteoric rise in recent seasons, progressing from the tenth tier of English football to the Premier League in less than a decade, but perhaps the rise has been too sharp and he needs more experience in the top divisions.
Brentford's director of football, Phil Giles, is hopeful this loan can benefit his development and that he'll be competing for a place in the line-up next season.
"Charlie has done very well when he has come into the team this season and last.
"However, he has not got enough game time in total in the last 18 months, so the best thing he can do is to try to get that elsewhere, ready to return to us in the summer and push on again next season. We wish him and Sheffield United well for the rest of the season.”