The opera house has signed a sponsorship deal with Travelex, a currency firm, to underwrite the offer. Travelex already sponsors a "Ô£10 Mondays" promotion.
Covent Garden already offers half-price standby seats four hours before performances begin. The new promotion allows students with appropriate ID to register for tickets either online or by text message a full 24 hours before the performance.
Tony Hall, the Royal Opera House chief executive, said, "It has been a wish of mine to find the best way to give students a change to come and see the work at the Royal Opera House. Standby seats have always been suitable for those audiences whose lives are more able to accommodate last-minute decisions."