
USA
Visa requiredA transit visa is REQUIRED to connect through the USA
The USA has no airside (sterile) transit — even if you only change planes you pass through immigration. Turkish citizens cannot transit via the USA without a valid C-1 transit or B1/B2 visa; you will be denied boarding.
Exemption. No problem if you hold a valid US visa (C-1 / B1 / B2) or a US green card.
Official source: travel.state.gov

United Kingdom
Visa requiredYou may need a DATV to transit the UK
Turkish citizens must obtain a Direct Airside Transit Visa (DATV) to transit airside through the UK (Turkey is on the DATV list). You remain in the transit area for up to 24 hours without passing immigration.
Exemption. AIRSIDE (DATV) exemption: a valid US/Canada/Australia/New Zealand visa, a permanent resident card for those countries, or an EEA/Swiss residence permit or category D visa — on this route you do NOT have to be travelling to that country. LANDSIDE transit (passing through border control) has a separate route: the Transit Without Visa (TWOV) concession. Its conditions: arrive and depart by air, hold a confirmed booking on a flight leaving before 23:59 on the day after you arrived, and hold ONE of the following documents (the main ones): (1) if you are travelling TO or FROM Australia, Canada, New Zealand or the USA, a valid visa for that country; (2) whatever your route, an Australian/Canadian/New Zealand permanent residence permit or a US green card; (3) whatever your route, an EEA/Swiss residence permit or category D visa. Electronic visas are NOT accepted for this concession, even printed. Check your own case on gov.uk.
Official source: gov.uk

Canada
Visa requiredA transit visa/permit is required through Canada
Turkish citizens are not eligible for Canada's eTA; a transit visa is required to connect by air through Canada. You cannot transit without a visa/permit.
Exemption. IMPORTANT: the Transit Without Visa (TWOV) program is NOT open to Turkish passports — only China, Indonesia, the Philippines, Thailand and Taiwan qualify. Holding a US visa does NOT exempt you in Canada. The only exemption: US lawful permanent residents (green card holders) may transit Canada without a visa.
Official source: canada.ca

Schengen area
ConditionalAn airport transit visa (ATV) may be needed via Schengen
Some Schengen countries (Germany, the Netherlands, France, Spain…) require Turkish citizens to hold an airport transit visa (type A / ATV) when connecting to a destination OUTSIDE Schengen.
Exemption. A valid Schengen visa (in some countries a valid US/Canada visa or residence permit) exempts you from the ATV. If your destination is itself in Schengen you will already hold a Schengen visa, so this connection is not a problem.
Official source: home-affairs.ec.europa.eu

China
ConditionalChina connection — 24-hour visa-free transit (conditional)
Turkish citizens are not included in China's extended 240-hour visa-free transit; only up to 24-hour visa-free transit (TWOV) applies, provided you hold an onward ticket to a third country and stay within the airport's restricted area.
Exemption. Under 24 hours, same airport, onward ticket to a third country → visa-free. Otherwise a China visa is required.
Official source: en.nia.gov.cn

Russia
Usually fineAirside transit in Russia is visa-free up to 24 hours
A connection of up to 24 hours at the same airport, without leaving the international transit area, is visa-free for Turkish citizens.
Exemption. If you leave the airport/transit area or switch to a different airport, a Russian (e-)visa is required. IMPORTANT — travel to or from Belarus or Kazakhstan via Russia: a Russian transit visa is required irrespective of how long you stay in Russia; the 24-hour exemption does not apply to those journeys.
Official source: dublin.kdmid.ru

USA
Visa requiredA special (green) passport also needs a US transit visa
A green passport grants no US visa exemption; there is no airside transit in the USA. Without a valid C-1 or B1/B2 visa you cannot connect through the USA.
Exemption. No problem with a valid US visa (C-1 / B1 / B2) or a US green card.
Official source: travel.state.gov

United Kingdom
Visa requiredThe UK transit rule also applies to a special (green) passport
A green passport grants no UK visa exemption; a Direct Airside Transit Visa (DATV) may be required for airside transit (Turkey is on the DATV list).
Exemption. The exemption routes are the same for a green passport: for AIRSIDE, a valid US/Canada/Australia/New Zealand visa or certain EEA/Swiss permits; for LANDSIDE, the Transit Without Visa (TWOV) concession — a confirmed flight leaving before 23:59 the day after arrival, plus one of these documents (the main ones): a valid visa for one of those four countries when travelling to or from it, or — whatever your route — an Australian/Canadian/New Zealand permanent residence permit, a US green card, an EEA/Swiss residence permit or a category D visa. Electronic visas are not accepted. Check on gov.uk.
Official source: gov.uk

Canada
Visa requiredA special (green) passport also needs a Canada visa
A green passport grants no Canada visa exemption (Turkey is not eTA-eligible); a transit visa is required to connect through Canada.
Exemption. IMPORTANT: the Transit Without Visa (TWOV) program is NOT open to Turkish passports and holding a US visa does NOT exempt you. The only exemption: US lawful permanent residents (green card holders) may transit Canada without a visa.
Official source: canada.ca

Schengen area
Usually fineA special (green) passport needs NO Schengen transit visa
Green passport holders enter the Schengen area visa-free for up to 90 days in any 180-day period, so an airport transit visa (ATV) is not an issue when connecting via Schengen — you may even leave the transit area and enter.
Exemption. Mind the 90/180-day rule; if your total stay exceeds 90 days a visa/permit is required.
Official source: mfa.gov.tr

China
Usually fineA special (green) passport — 30 days visa-free to China
Green passport holders may enter China visa-free for up to 30 days, so the 24-hour transit limit does not apply to you when connecting via China; you can enter/transit freely.
Exemption. For stays over 30 days a China visa is required.
Official source: mfa.gov.tr

Russia
Usually fineA special (green) passport — 30 days visa-free to Russia
Green passport holders may enter Russia visa-free for up to 30 days, capped at 90 days in any 180-day period, so leaving the transit area and entering is not a problem either.
Exemption. A Russian (e-)visa is required for stays over 30 days, or once your total exceeds 90 days in any 180-day period. For travel to or from Belarus or Kazakhstan via Russia, however, the Russian consulate states that a Russian transit visa is required regardless of the length of stay — confirm with the consulate whether your visa-free entry covers that journey.
Official source: mfa.gov.tr