Generally no — Excedrin already contains aspirin (an NSAID), so taking it with ibuprofen (also an NSAID) means doubling up on NSAIDs, which raises the risk of stomach bleeding and ulcers; check with a pharmacist before combining.
Excedrin (Extra Strength and Migraine) is a combination of acetaminophen 250 mg, aspirin 250 mg, and caffeine 65 mg per tablet — and aspirin is a nonsteroidal anti-inflammatory drug (NSAID). Ibuprofen is also an NSAID, so taking the two together stacks two drugs of the same class. The NHS states plainly: "Do not take ibuprofen at the same time as other non-steroidal anti-inflammatory drugs (NSAIDs), such as naproxen or aspirin," because it increases the risk of stomach ulcers and bleeding; its aspirin page likewise advises "do not take aspirin with ibuprofen or naproxen without talking to a doctor." The FDA-approved Excedrin label carries an NSAID stomach-bleeding warning and specifically lists taking "other drugs containing prescription or nonprescription NSAIDs (aspirin, ibuprofen, naproxen, or others)" as a factor that raises bleeding risk.
The concern is additive NSAID toxicity: stomach ache, stomach ulcers, and internal bleeding — warning signs include severe or persistent stomach pain, vomiting blood, or black/tarry stools, which warrant urgent medical attention. Risk is higher if you are 60 or older, have had ulcers, take blood thinners or steroids, or have 3+ alcoholic drinks a day. If you need extra pain relief on top of Excedrin, the NHS notes paracetamol (acetaminophen) can be taken alongside ibuprofen — but Excedrin already contains acetaminophen, so do not exceed the label maximum (8 tablets in 24 hours for Excedrin Extra Strength; 2 caplets in 24 hours for Excedrin Migraine), since severe liver damage can occur above the limit, and watch your total acetaminophen from all sources. Separately, if you take low-dose aspirin to protect your heart, the FDA has warned that ibuprofen can interfere with that protection — ask your pharmacist about timing. Bottom line: don't routinely combine Excedrin with ibuprofen — ask a pharmacist or doctor before mixing them, especially if you have any of the above risk factors.
This is general reference, not medical advice, and not a guarantee of safety. Interactions depend on your doses, health conditions, and other medicines. Always confirm with your pharmacist or doctor before combining products, and follow the dosing on each label.