Both had different managers and vastly different squads. Neither went up that year - but look at them now.
With both flying high in the Premier League, it's worth looking back at a moment neither Watford nor Leicester fans will ever forget, for very different reasons.
Indeed, during their famous play-off semi-final almost three years ago, the two clubs served up a pre-cursor to the drama they are now offering the top flight.
Leicester could be about to shock the world of sport as they sit top of the Premier League table with 12 games to go. Watford, meanwhile, are ninth - an impressive feat considering the Foxes were fighting relegation this time last year (during their first season after going up).
Watford's leading man this term Troy Deeney was just as important when the Hornets denied Leicester a place at Wembley in 2013. The visitors had the chance to net a last-gasp penalty to secure their play-off final spot - but it was saved.
And what happened next was one of the most memorable moments in recent football history (if not ever). Watch for a reminder if you're not exactly sure!