Five quarterbacks went in the first 10 picks of the draft with no defensive players selected.
All three of the top draft picks were used to select quarterbacks, with The Washington Commanders choosing Jayden Daniels from Louisiana State University and the New England Patriots opting for North Carolina signal-caller Drake Maye.
The Bears' choice of Williams was widely expected, with the 2022 Heisman Trophy winner seen as the answer to the franchise's long-running problem at the position.
Last month, the Bears traded their quarterback Justin Fields, a first-round pick in 2021, to the Pittsburgh Steelers.
Williams began his college career at Oklahoma before switching to USC and in 37 games, with 33 starts, he threw for 9,782 yards and 93 touchdown passes with an additional 27 rushing touchdowns.
"It took a lot of sacrifice, love, care for winning the game of football and my team-mates, my coaches and my family," said Williams, when asked how he had become the top draft pick.
The Bears provided Williams with a wide receiver with the ninth pick opting for Washington's Rome Odunze.
Daniels played a total of 55 games in college football, beginning with Arizona State before joining LSU and in 55 games he threw for 12,750 yards and 89 touchdowns and added 3,307 rushing yards and 34 rushing touchdowns.
The Patriots were taking part in the draft without Bill Belichick as their head coach for the first time since 1999 and they will hope Maye can end their search for a quarterback to finally replace Tom Brady.
In a quarterback-heavy top of the draft, the Atlanta Falcons surprisingly opted for Michael Penix Jr out of Washington with the eighth pick despite recently signing a quarterback in Kirk Cousins.
Penix is a highly-rated quarterback but was expected to have fallen down the draft due to concerns over a series of injuries he has suffered including two anterior cruciate ligament knee injuries.
To replace Cousins, the Minnesota Vikings moved up a place in the draft to take Michigan quarterback J.J. McCarthy with the 10th pick.
There had been speculation that the New York Giants might make a move for a quarterback with their sixth pick but they opted for a wide receiver in Malik Nabers from LSU.
The Los Angeles Chargers took an offensive tackle in Joe Alt out of Notre Dame and the Tennessee Titans also took a player in that role, drafting Alabama's JC Latham.
