"I'm very excited that Karlos, Josue and Nick have decided to stay and continue their careers at Florida State," head coach Jimbo Fisher said in a press release. "They're more pieces to the puzzle of our success. They've all contributed to helping the program get to where we are today. We believe another season will help them continue to develop and expand on their NFL potential."
Williams rushed for 730 yards and 11 touchdowns on 91 carries while splitting duties in the backfield. Matias was a second-team All-ACC selection who has started 29 straight games on the offensive line dating to the 2011 season.
O'Leary was a finalist for the John Mackey Award as the nation's top tight end, finishing 2013 with 33 catches for 557 yards and seven touchdowns. He was a second-team All-ACC pick and led all tight ends nationally by averaging 16.9 yards per catch.
Jernigan capped his FSU career with nine tackles in Monday's championship game. He led FSU with 11 tackles for loss this year and had 63 tackles on the season, good for third on the team.
"I'd like to thank my coaches - Coach Fisher, Coach (Odell) Haggins and Coach (Jeremy) Pruitt - on guiding me and developing me into the player I am today," Jernigan said in the release. "I'd like to thank my teammates. I couldn't have had the success I had without them. I wouldn't have wanted to play with any other group of guys. It's really hard to walk away from a place like Florida State. We accomplished so much this season, and I'm glad I was a part of it. It's been a good three years, but it's rare to get an opportunity like I have and I'd like to take advantage of that opportunity right now."
Although 2014 was his first year as a starter, Jernigan is Florida State's biggest loss to the NFL yet.
"Timmy was one of the leaders on our defense and a big part of our success these past three seasons," Fisher said. "He was one of the most dominant defensive lineman I've been around in all my years coaching. Not only was he a dynamic football player, but he was also a great person. We expect Timmy to be very successful at the next level and we wish him the best."
Williams, Matias and O'Leary join junior wide receiver Rashad Greene, junior right guard Tre Jackson and redshirt junior left tackle Cameron Erving in returning to school. They announced their decision to return on Wednesday night.
Greene will enter his senior season as one of the most productive receivers in Seminole history. He has led FSU in receptions and yards each of the last three seasons. He ranks fourth in school history with 171 receptions, sixth with 2,465 receiving yards and seventh with 22 touchdown catches. The 6-foot, 180-pound receiver had nine catches for 147 yards in the national championship on Monday, both season highs.
"We aren't finished with what we started here at Florida State," Greene said in the release. "These are my brothers and we are continuing to build something special in Tallahassee. After talking with Coach Fisher, Coach (Lawrence) Dawsey and my family, I know that this is the best decision for my future. I want to finish my degree and improve as a player and a leader while helping FSU capture even more success with my teammates and coaches next season."
Erving, a 6-foot-6, 330-pound converted defensive tackle, has started each of the last two years on the offensive line. He won the Jacobs Blocking Trophy as the ACC's top blocker as voted on by the league coaches and defensive coordinators this season.
He was a first-team All-America pick by The Sporting News, USA Today, and SportsIllustrated.com this season.
"We have something really special going on here at Florida State," Erving said in the release. "Of course, I want to be a part of that. I want to mature and grow as a player before I make that big step to the NFL. I enjoy playing for Coach (Jimbo) Fisher and I love the support of our fans. This decision is the best for myself and my family. I'm coming back to school to finish my degree, to improve as a player and lead the Seminoles to another successful season during my last year of college football."
Jackson has started 28 games on the offensive line for his career. The 6-foot-4, 330-pounder earned second-team All-America honors from CBS Sports this year and an honorable mention on SportsIllustrated.com's All-America team.
"After talking to my family and coaches, I decided the best decision for me is to return to Florida State for my senior season," Jackson said in the release. "I want to build on the success we had this season and improve as a player while finishing my degree."
The trio helped FSU score a record 723 points this season while averaging 519.1 yards per game.
"I'm very excited for Cam, Rashad and Tre' to be coming back to our program," Fisher said. "They were major impact guys for us this year. I think they will all have tremendous careers here at Florida State. After each of them met with their families and our coaches, and all the information was gathered, they each decided it was best for their future that they return to Florida State. We are very excited to have them back.
"We are looking forward to having another great season. As they said - we're not finished with what we started. Those three guys are a huge part of our future."
The school also confirmed on Wednesday junior running back James Wilder Jr. would enter the NFL draft. Wilder finishes his FSU career with 226 carries for 1,358 yards and 20 rushing touchdowns. He also has two receiving touchdowns.
"James contributed a lot to our success these past three seasons," Fisher said. "We wish him the best in his future endeavors."
The deadline for underclassmen to declare for the draft is Jan. 15. The 2014 NFL Draft will take place from May 8-10 in New York City.