Not if you stay airside in the same terminal. You will re-clear security if you change terminals without an airside link, leave the airport, or arrive internationally into a country (like the US) that makes everyone clear immigration and customs.
Airside connection: most hubs (SIN, DOH, DXB, HKG, IST, AMS, FRA T1, ICN) let you connect without re-screening, though a transfer security check is common when arriving from some countries.
Terminal change: at JFK, LAX (T1/T2), LHR, CDG and ORD a terminal change often means leaving the secure area and re-clearing.
Arriving in the US: every international arrival clears immigration and customs, collects bags (unless the airline participates in a bag-through program), re-checks them and re-clears security. Allow three hours.
Schengen: connecting from a non-Schengen flight to a Schengen one means passport control (and now EES biometrics), but not always a new security screening.
Related questions
What is a layover, and how is it different from a stopover?
A layover is the time between connecting flights on one ticket — usually under 24 hours. A stopover is a deliberate stay of more than 24 hours (often days) at the connecting city, sometimes offered free by hub airlines. Full answer →
What happens if I miss my connecting flight?
On a single ticket, the airline rebooks you on the next available flight at no charge, and may owe meals or a hotel if the delay was its fault. On separate tickets you're on your own — you'll buy a new ticket. Full answer →
Airline, airport and government rules change without notice. Treat this as a starting point and confirm with the airline or authority for your specific trip. Request a correction if something is out of date.