Slow Horses characters ranked: From Jackson Lamb to River Cartwright

From Gary Oldman's Jackson Lamb to Christopher Chung's Roddy Ho and Aimee-Ffion Edwards as Shirley Dander, each of them brings something different to the table, each with the capability to be both laugh-out-loud funny and also quietly devastating.

Who is the best of the best? That's impossible to tell. Everyone will have their favourites, though, and I certainly have my own, the top 20 of which we have ranked below.

It should be noted, this is based solely on the characters as presented on screen, not on their presentation in the books.

Now, without further ado, read on for my full ranking of the 20 best characters in Slow Horses – so far.

*Warning – contains spoilers for seasons 1-4 of Slow Horses*

15. Joanna Scanlan as Moira Tregorian

Moira only appeared in one season of the show – season 4 – but in that time she made a big impression. The replacement for Catherine Standish may not hold a candle to her predecessor, but she is an enjoyably mismatched addition with her locale, and her attempts to get Slough House in to some sort of order were a joy to behold.

Of course, her appearance in this ranking isn't hurt by the fact she is played by the delightful Joanna Scanlan, who has been perfectly cast here, and who showrunner Will Smith has clearly written to specifically based on their previous work together in The Thick of It. Her final moments on screen, in which she pressured Claude Whelan into giving her back her job at the Park, showed her to be a force to be reckoned with.

14. Hugo Weaving as Frank Harkness

Introduced in season 4, Frank Harkness at first acts as that run's biggest mystery, before coming into focus at the end when it is revealed he is River's father. Sure, he's a bit of a cartoon villain, but if you're going to do a cartoon villain you get Hugo Weaving to play him, don't you?

The star navigates the road between being utterly magnetic yet hugely threatening at the same time, no mean feat given his fairly insubstantial screen time. We know we haven't seen the last of him yet, and it does feel like there is still more to delve into with his character, but as of writing he is still already the best full-on villain the show has had to offer thus far, and that shouldn't be ignored.

13. Ṣọpẹ́ Dìrísù as Sean Donovan

Another one-season wonder, Ṣọpẹ́ Dìrísù's Sean Donovan thoroughly earned his place on this list across the six episodes in which he appeared. Taking on a central role in season 3, and driving the plot of that run, he perfectly exemplified the show's primary interest in complex, murky, morally grey characters.

The fact that Dìrísù also brought a realism and a charm to the role which could have otherwise just been a plot device means he was a very welcome addition to that run of the show, and stands out amongst the show's guest characters.

12. Kadiff Kirwan as Marcus Longridge

Marcus is a character who never entirely felt like he got his due. He was always a welcome presence on the team (as was actor Kadiff Kirwan on screen), and despite his own flaws and issues, a real voice of reason, working as the perfect offset to Shirley, Roddy and some of the other members of Slough House.

His very presence on this list is testament to that – there are plenty of characters, even pretty central ones, who didn't make the cut. However, his tragic death at the end of season 4, while shocking and affecting, did mean we missed out on learning more about him and his past, getting to know him on a deeper level beyond his dynamic with other characters.

11. Jonathan Pryce as David Cartwright

David was often used more as a plot device than a character in his own right in the show's earlier seasons, a foil to Jackson Lamb and a reason for his behaviour towards River. But as his arc came into sharper focus in season 4, and he was given more depth, the character became more of a tragic figure, and thus more interesting.

Of course, Jonathan Pryce has been one of the show's biggest casting coups, and everything he is given he excels at. As we have seen the character go through the early stages of dementia, his relationship with River has taken on new nuances, and become one of the beating hearts of the series.

10. Aimee-Ffion Edwards as Shirley Dander

Shirley is a character who, like Marcus for many of the show's seasons and episodes thus far has been defined more by her relationships with the other Slough House members, perhaps simply because she's so combative and abrasive. This has kept her a little bit at arm's length from us.

However, in season 5 we start to get to know her better, a challenge Aimee-Ffion Edwards is more than up to. As she continues to come to terms with Marcus's death, and tries to maintain her sobriety, we start to understand her more than we have before, even as the show still lets Shirley be Shirley – she's not going to become shy and retiring anytime soon, and long may it last.

9. Tom Brooke as JK Coe

Based solely on his appearance in season 4, you may be wondering why JK Coe appears as high up this list as he does. He had a standout moment at the end of the season, when he finally got in on the action and nonchalantly killed Patrice after talking Shirley out of doing so. But for the most part, he was in the background, refusing to give much away beyond his really rather threatening aura.

In some ways, we're cheating a bit here, because Coe's ranking is also based on his role in the remainder of season 5, which is something to behold. As you wait for those later episodes, just know that there's a lot more to come from Coe, with these scenes being excellently brought to life by actor Tom Brooke.

8. Dustin Demri-Burns as Min Harper

Ah, Min. Poor sweet Min, whose time on the show was cut tragically short in season 2. His relationship with Louisa was one of the show's brightest spots of pure joy in these spies otherwise quite miserable lives, and it was all excellently played by both Rosalind Eleazar and also Dustin Demri-Burns, who was so charming and fun here so as to leave an indelible mark on the series and its fans, in a way few other shorter-term characters have done.

Demri-Burns's comedy background was clear from the off, but his dramatic chops cannot be understated, making Min someone we could all truly root for.

7. Saskia Reeves as Catherine Standish

Catherine Standish is the ultimate unsung hero of Slow Horses. Constantly underestimated due to her age, her mild manner and her history of addiction, Standish is really the one who keeps the Slough House ship afloat, is the only one who has a chance of keeping Lamb in check, and often the only one who can see the wood for the trees when it comes to the team's various cases.

She's not just workmanlike though. Sakisa Reeves makes her both a heartfelt and humorous presence. It's no wonder that she was back so soon after quitting Slough House at the end of season 3 – Standish really is indispensable.

6. Christopher Chung as Roddy Ho

What an utterly loathsome character Roddy Ho is. A man who is utterly solipsistic, completely lacking in empathy and utterly unsuited to being part of a team. That is exactly why he appears as high up as he does on this list. Of course, Christopher Chung manages to imbue him with slightly more likability than could otherwise have been the case, but really the reason we love Roddy is because he's so repulsive and utterly unrepentant.

Most shows in their fourth or fifth season would feel the need to make a character as central as Roddy slowly start to develop a heart, to become more palatable to the general audience and show some growth. The fact that Slow Horses refuses to do so, and continues to revel in his refusal to change, is part of why fans embrace it as much as they do.

5. James Callis as Claude Whelan

Probably the most controversial placement on this list, I imagine some fans will be a bit baffled by Claude's ranking here. The truth is, there's just something about Claude. Almost every scene he's in makes me laugh – James Callis has terrific comic timing and delivery, and his dynamic with Taverner is absolutely delicious.

He's also just so expertly observed. Most people will know someone like this in their life, someone who is not necessarily a bad person, but a flawed and incompetent one, someone who is so out of their depth that it becomes actively aggravating, and even dangerous. If we were ranking characters based on how closely you would want to work with them, Claude would be pretty low on this list. But for pure entertainment value, he excels.

4. Kristin Scott Thomas as Diana Taverner

As much as I love Claude, he really couldn't beat Kristin Scott Thomas's Diana Taverner to the punch – not again. Taverner is a crucial ingredient to the show's success, adding a crucial level of tension to proceedings while also being that rare thing in the world of Slow Horses – she is, for the most part, pretty efficient and good at her job. Of course, "good" is an arguable term here.

Taverner is in no way an agent of rectitude, but someone who sees the world in all of its shades of grey, and will certainly act in the interest of the country and the agency – just not, necessarily, before her own interests. The fact that we don't see as much of her across the series only makes her more intriguing. We can never quite know what she's thinking, in part thanks to Scott Thomas's brilliantly cutting portrayal, and that makes her that rare character where you never quite know what she's going to do next. It's thrilling to watch.

3. Rosalind Eleazar as Louisa Guy

One of the most relatable, pragmatic and down-to-Earth of the Slough House team, Louisa is also one of the most efficient agents, and thrilling to watch in an action set piece. She's not exactly a bundle of light and sunshine, and can certainly be a tough nut to crack, but the fact that she is still so engaging as a character and such a draw is a testament to the show's sharp writing and Rosalind Eleazar's impressively empathetic portrayal.

Her dynamics the likes of with River, Min and Marcus have been some of the best on the show, yet she is also a force in her own right, who we would happily watch go off on her own mission. Sure, she'd grumble along the way, but unlike some of the others we'd understand her gripes – like Standish, she is so often a source of sense in this insane world, something which is sorely needed.

2. Gary Oldman as Jackson Lamb

It's pretty inarguable that Slow Horses would be anywhere near the hit that it is without either Gary Oldman or his take on Herron's most recognisable character, Jackson Lamb. Across the five seasons thus far, Oldman has completely embodied that role, and it's always been clear, perhaps more than anyone, just how much fun he's having here. The character is a brilliant combination of at once being an enigma, with a past we only ever see glimpses of or find out about piecemeal, yet also being so brazen, so brash, so out in the open with all of his flaws.

Like with Roddy Ho, Jackson is not a character who is looking for redemption, or who we are likely to see 'change his ways' anytime soon. Even his small moments of kindness or open humanity, such as securing Marcus's salary for his family or having a drink with River at the end of season 4, are couched in barbs and hostility. Perhaps the best thing about Lamb, beyond being one of the funniest characters on the show while also carrying a sense of darkness, is that you always sense he has an ace up his sleeve and a plan in place – you just don't know what that plan is, or how it will impact the others.

1. Jack Lowden as River Cartwright

The final two placings of this list were on a knife edge. Could we really put someone who isn't Jackson Lamb at the top?

In truth, neither Jackson nor River would work nearly as well as the centre of this series without the other, with their dynamic and their duelling personalities proving in many ways to be the show's secret sauce. However, the reason River just ekes ahead to the top of this list is his humanity. Lamb is endlessly fascinating, hilarious and a bundle of quirks and characteristics, but River shoulders the emotional burden of the series – the whole show relies on us engaging with him on a deeper level, and the truth is, we really do.

Jack Lowden is fantastically well-cast, and has been getting better in the role with each season. The character is not a cut and dry action hero, he's deeply flawed, egotistical and often reckless, yet we root for him all the same. On another day, this list could change and Jackson could come out on top – but today, River takes the crown.

New episodes of Slow Horses season 5 arrive on Apple TV+ on Wednesdays. Seasons 1-4 are available to watch now – sign up to Apple TV+ here.

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