The Ultimate Ranking of Castle TV Show Seasons

Season 1

The pilot of Castle is one of the strongest ever seen for a crime drama. Each character is established effortlessly, and it's instantly easy to relate to and care about these characters. It's an iconic start to the series.

Beckett, Ryan, and Esposito in Castle season 1 episode Flowers For Your Grave

Season 1 quickly rose above the other offerings on television at the time, with no question about who the characters are and what motivates them.

The first season of Castle is an iconic start to the series, with a pilot that is one of the strongest ever seen for a crime drama.

Season 2

Season 2 doesn't push itself too far outside the murder-of-the-week format, but includes some genuinely scary episodes with higher stakes than ever before. It's committed to not letting the leads cash in on their chemistry too early, which is commendable.

Castle and Beckett with a man dressed as a vampire in Castle Season 2 episode Vampire Weekend

After the success of season 1, Castle was able to start defining itself as a unique show in the television landscape, and try new things in the second season.

Season 2 includes some genuinely scary episodes with higher stakes than ever before. It's a unique show in the television landscape, and tries new things.

Season 3

Season 3 puts Castle and Beckett in many life-threatening situations, and the investigation surrounding Beckett's mother's murders ramps up in a great season-long arc.

Beckett and Castle in Castle season 3 episode Countdown

Season 3 started to see the writers incorporate more meta elements in the scripts, as well as pushing the actors to express their characters' development.

Season 3 puts Castle and Beckett in many life-threatening situations, and the investigation surrounding Beckett's mother's murders ramps up in a great season-long arc.

Season 4

Season 4 is a close second when it comes to the best season of the show. It has some of the most inventive episodes of the series, and the building romance between Beckett and Castle is going to explode off the screen.

Castle and Beckett in Castle season 4 episode Blue Butterfly

The season stands out because it goes through a reinvention with new characters introduced, and starts to shine a light on the arcs of the characters outside Beckett and Castle.

Season 4 has some of the most inventive episodes of the series, and the building romance between Beckett and Castle is going to explode off the screen.

Season 5

Season 5 kicks off with the moment everyone had been waiting for, Beckett and Castle have just spent the night together, and have to determine what this means for them and their relationship.

Beckett in Castle season 5 episode After The Storm

Seeing years of tension and chemistry pay off is well worth watching, and the newly romantic dialogue is just as strong as the combative friction of earlier seasons.

Season 5 illustrates how compatible Beckett and Castle are, combining mystery with a tone that doesn't take itself too seriously, and isn't afraid to make the audience laugh.

Season 6

Castle and Beckett were fully together by season 6 and had fallen into a rhythm about how to behave as a couple and as investigative partners.

Castle and Beckett in Castle season 6

The character traits that had been established throughout the first five seasons were traded in for ones that kept the narrative interesting. Specifically with Beckett, who finds her engagement to Castle, which occurs at the start of the series, an obstacle to her usual brand of independence and self-awareness.

The penultimate episode of the season, 'Veritas', finally resolves the arc of the murder of Beckett's mother, providing a satisfying conclusion to this storyline.

Season 7

Season 7 has its strong points, but fails in many of the same ways as season 8. In an attempt to be more serialized, the season features a recurring villain and explores Castle's backstory, but the conflicts feel forced and don't have the stakes of earlier seasons.

Castle and Beckett in cowboy outfits in Castle season 7 episode Once Upon A Time In The West

The episode, 'The Time of Our Lives', features the Caskett wedding that had been brewing for the show's entirety finally happened, which was a season-high.

Season 7 fails in many of the same ways as season 8, with conflicts that feel forced and don't have the stakes of earlier seasons. However, the Caskett wedding that had been brewing for the show's entirety finally happened, which was a season-high.

Season 8

Season 8 is the worst and most disappointing season of Castle, as it has none of the Caskett screentime that makes the show worth watching, and most of the cases had lost their edge by this point.

Castle dancing on a cruise ship in Castle season 8 episodes Mr. and Mrs. Castle

Katic and Fillion were reportedly having a difficult time working together, which led to storylines that kept their characters apart for most of the season, making it hard to watch.

Castle and Beckett in Castle season 8

Initially, the show was supposed to be renewed for a ninth season, but Katic would not have returned. By what turned out to be the final season, Katic and Fillion were reportedly having a difficult time working together, which led to storylines that kept their characters apart for most of the season.