Chicago airport lounge access at O'Hare (ORD) splits two ways: airline lounges such as the United Club, American Admirals Club, and Delta Sky Club serve their own passengers and members across the domestic terminals, while Priority Pass access is concentrated in Terminal 5, the international terminal. Chicago airport lounges cost varies by route: airline clubs typically require membership, elite status, or a same-day eligible ticket rather than a flat walk-up price, and Priority Pass lounges are covered by your membership rather than a separate fee, so budget around your credentials, not a fixed rate.
For airline lounges, United operates United Club locations for its members, elite frequent flyers, and eligible premium-cabin passengers, concentrated near its home concourses. American runs Admirals Club lounges for its own members and qualifying travellers, and Delta operates Delta Sky Club locations for Sky Club members, Delta elites, and eligible premium tickets. Each brand's lounges are built around that airline's own membership and status system rather than a pay-at-the-door model, so check your airline account for the closest option to your gate.
Chicago airport lounges Priority Pass coverage is narrower than the domestic club network. The Priority Pass lounges at O'Hare sit in Terminal 5, the international terminal, and are separate from the United, American, and Delta clubs in the domestic terminals. If you hold Priority Pass through a travel card such as certain premium rewards cards, plan on Terminal 5 for that benefit rather than expecting it to work at a domestic-terminal airline club.
Because O'Hare is enormous and split across multiple terminals, the practical approach is to match your access method to your terminal before you arrive: airline status or membership for the United, American, or Delta clubs in the domestic terminals, and Priority Pass for Terminal 5 if you are flying internationally. Confirm specific hours and eligibility with your airline or card issuer, since lounge rules and locations do shift over time at a hub this size.