AirHint found the following cheapest return flights from Chicago (MDW) to Porto (OPO) in March 2026 (see full year).

Return flights

03 Mar - 10 Mar	KLM
02 Mar - 09 Mar	KLM
04 Mar - 11 Mar	KLM
09 Mar - 16 Mar	KLM
10 Mar - 17 Mar	KLM
24 Mar - 31 Mar	KLM
05 Mar - 12 Mar	KLM
16 Mar - 23 Mar	Air France
17 Mar - 24 Mar	KLM
01 Mar - 08 Mar	KLM
25 Mar - 01 Apr	Delta
31 Mar - 07 Apr	Delta
26 Mar - 02 Apr	Delta
29 Mar - 05 Apr	Delta
30 Mar - 06 Apr	Air France
27 Mar - 03 Apr	Delta
28 Mar - 04 Apr	Air France

Also check the deals for one-way flights from Chicago to Porto in March.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

Book a cheap hotel in Porto

Cheap car rent in Porto

Cheapest return flights from Chicago to Porto in March from 452€

Return flights