Which Current Long-Serving UFC Champions Haven’t Yet Defended Their Undisputed Championship?

Picture Tom Aspinall seeing the notification. Alex Pereira vs. Cyril Gane — interim heavyweight title, on the biggest card of the year at UFC Freedom 250, at the White House no less. His division. His belt. Another interim champion being manufactured while he sits at home waiting for medical clearance on a double eye surgery he needed because Gane accidentally put two fingers in his face in Abu Dhabi.

The UFC currently has no fewer than 12 champions. Only two of them have defended their straps: Alexander Volkanovski beating Diego Lopes on home turf in Sydney back in February, and Valentina Shevchenko defending against Manon Fiorot and Zhang Weili last year. That’s the state of the UFC in April 2026 — a collision of emergency surgery, retirement phone calls, personal crises no training camp could prepare for, and a heavyweight title picture so cursed it borders on mythology.

The three champions who’ve been sitting longest without a defense — Harrison, Aspinall, and Topuria — each have a completely different story. None of them are simple.

Ilia Topuria: Champion Since June 28th, 2025

Here’s the political reality of Ilia Topuria’s entire lightweight reign: it was built on a fight that never happened. He vacated the featherweight gold in February 2025 with lightweight king Islam Makhachev locked in his sights — the dream unification of the two most naturally gifted champions in the sport. Then the Dagestani vacated his title as well, jumping to welterweight. Dream fight, gone. Was he avoiding El Matador? Or simply chasing the greatness that coach and confidant Khabib Nurmagomedov achieved?

Topuria took what was available: Charles Oliveira for the vacant 155-pound belt at UFC 317 last June, knocking out “Do Bronx” in vicious fashion and becoming a two-division champion in the process. Then Topuria vanished. No fights in the nine months since.

Ilia Topuria is officially the biggest star in Spain 🇪🇸🌹 pic.twitter.com/bcw7cfiwu9

— Bovada (@BovadaOfficial) June 30, 2025

In November 2025, he announced he wouldn’t compete in Q1 of 2026 due to personal issues, later clarifying that serious family matters and false stories circulating about his private life made genuine fight preparation impossible. The UFC responded by booking Justin Gaethje vs. Paddy Pimblett for an interim lightweight title at UFC 324 on January 25th, and it was the American veteran who was dominant, picking up a wide unanimous decision win and snapping his brash British opponent’s nine-fight win streak.

Now, however, Topuria’s prolonged absence is set to come to an end, and it does so on a blockbuster card on the White House lawn. UFC Freedom 250, June 14th, headlined by the crunch unification fight between Topuria and Gaethje, and online betting sites make El Matador the man to beat. The latest UFC lines Bovada currently position the Georgia-born Spaniard as a mighty -585 favorite to finally defend the gold. Will he live up to the billing? Or will his time out of the Octagon prove to be his undoing?

Tom Aspinall: Champion Since June 21st, 2025

69 seconds. That’s how long it took Tom Aspinall to stop Sergei Pavlovich in November 2023 and announce himself as the most dangerous heavyweight on the planet. Interim champion. Then nothing for nineteen months — the longest interim title reign in UFC history — while Jon Jones played chess with the matchmakers, negotiated endlessly, and ultimately refused to fight the mandatory challenger not by losing or being stripped, but by phoning the UFC on June 21 of last year to announce his impromptu retirement.

Aspinall was elevated to undisputed champion by announcement. No unification fight. No octagon moment. A press release coronation for a man who’d done nothing but everything right.

His first actual defense was at UFC 321 in Abu Dhabi last October against the same Ciryl Gane set to fight at the White House. He was competitive. Gane was sharp. Then, at 4:35 of the opening round, Gane’s fingers went clean into Aspinall’s eyes. Both of them. Aspinall told the cageside doctor, “I can’t see.” After a five-minute timeout, referee Jason Herzog called the fight off. No-contest. The first UFC title fight to ever end by accidental foul.

Double eye surgery followed. The heavyweight title — Aspinall’s by every legitimate measure — is now the centerpiece of a division building around him while he recovers. Alex Pereira will move up in weight to fight Gane for the interim title at UFC Freedom 250, with the Brazilian aiming to become the first three-weight champion in history. Aspinall will likely fight the winner, whoever that may be, later this year.

Kayla Harrison: Champion Since June 7th, 2025

On January 14, 2026, Kayla Harrison posted a video wearing a neck brace and hospital garb, one day after surgery to repair two herniated discs. She was crying. She apologized to fans. She apologized to Amanda Nunes. “I was really eager for this matchup,” she said, voice breaking. Ten days before UFC 324. Ten days before the biggest fight in women’s MMA history — the greatest female fighter of all time, who came out of retirement specifically to fight Harrison, was waiting at the other end. Harrison pulled out of her coronation moment. The kind that happens once.

Two Olympic judo gold medals. Two PFL championships. Signed by UFC in January 2024. She debuted at UFC 300 with a second-round rear-naked choke of Holly Holm — a living legend, finished — then beat Ketlen Vieira by unanimous decision at UFC 307 in October. When she stepped into the co-main event of UFC 316 on June 7, 2025, in Newark and submitted Julianna Peña with a kimura at 4:55 of Round 2, she became the seventh undisputed women’s bantamweight champion in UFC history — and the first fighter ever to hold Olympic gold and a UFC title.

The UFC didn’t strip her. They didn’t create an interim belt. That decision tells you exactly how badly they want Harrison vs. Nunes — it’s too big, too rare, too culturally significant to dilute with a placeholder. But Nunes isn’t getting younger, and patience isn’t infinite.

Will the fight actually get made before the window slams shut permanently? Harrison appeared on a UFC Paramount+ preview show on April 25th and delivered the line everyone needed: “Your girl’s back, baby.” No confirmed date. No official opponent. Just a champion in recovery, declaring herself ready. The clock is now ticking — and every week that passes without a fight date is a week where the greatest possible version of this matchup edges slightly further away.