They won only three of their first six games, losing by greater than 40 points to the Brisbane Lions, Port Adelaide and Geelong, placing the Eagles 12th on the ladder at the end of round six.

The assistant coaches were Jaymie Graham (forwards),[10] Nathan van Berlo (midfield),[11] Daniel Pratt (backs),[12] Adrian Hickmott (contested ball coordinator),[13] and Matt Rosa (stoppages and structure).

[15] In March, Sam Kerr, the captain of Australia's women's national soccer team, was announced to be West Coast's number-one ticket holder for 2019–20.

[17][18] West Coast's major sponsors for 2019 were fast food outlet Hungry Jack's and online mortgage broker Lendi.

[22] Scott Lycett left the club under the AFL's free agency rules, taking an offer from Port Adelaide in his home state of South Australia.

Ryan Burrows, Callan England, Tony Olango and Tarir Bayok, who were all on the rookie list and did not play any AFL games, were also delisted.

[24] On 7 October 2018, the day before the start of the 2018 trade period, Andrew Gaff signed a new contract with West Coast, after much consideration to leaving under the AFL's free agency rules.

Having been suspended for eight weeks near the end of the 2018 season for striking Fremantle player Andrew Brayshaw in the jaw, Gaff was considering signing a contract with a club based in Victoria, his home state.

Six clubs looked at potentially recruiting Gaff, including North Melbourne, who offered him a seven-year long deal worth about $8 million.

In the end, he chose to stay with West Coast, in the hopes of winning a premiership, signing a contract there worth less than the North Melbourne one.

[27] Obtaining an experienced ruckman to replace Lycett while Nic Naitanui was recovering from injury was West Coast's top trade priority.

[28][29] West Coast were also aiming for a trade with Geelong for Tim Kelly, who wanted to return to his home state of Western Australia.

[52][53] Going into the start of the season, Nic Naitanui, Andrew Gaff, Jamie Cripps, Josh Kennedy and Willie Rioli were unable to play.

[54] Gaff had been out due to an eight match ban received for striking Fremantle player Andrew Brayshaw in the jaw in round 20, 2018.

[60][61] Liam Duggan did not play due to a knee injury,[62] with Josh Rotham making his AFL debut as replacement.

[63] In round four was the season's first Western Derby, the biannual home-and-away match between West Coast and their cross-town rivals Fremantle.

Saints fans were angry at the 7–3 free-kick count for the first half, including two free kicks that resulted in West Coast goals.

Liam Ryan took a spectacular mark on top of 208-centimetre (6 ft 10 in) Melbourne ruckman Max Gawn, before kicking a goal to give West Coast the lead in the final ten minutes.

The Crows entered half time 28 points ahead of West Coast, who kicked no goals in the second quarter, compared to Adelaide, who had five.

[90][91] Willie Rioli and Nathan Vardy both received a one match suspension for rough conduct against Colin O'Riordan and Jackson Thurlow respectively.

[96] In round 15, Nic Naitanui made a much-anticipated return from injury to the AFL, having played one match for the Eagles' WAFL team the previous week.

West Coast were unable to score any goals for the last quarter and a half, allowing Collingwood to come back from an 18-point margin.

[103][104] A late withdrawal by Shannon Hurn due to a calf injury enabled Francis Watson to make his debut.

[111] In round 22, West Coast faced Richmond, 2018's minor premiers, in what AFL.com.au called the "game of the season", and a possible preview for the Grand Final.

[113][114] Going into their round 23 match against Hawthorn, almost all expectations were that West Coast would win, and finish the home-and-away season firmly in the top four.

[115] Instead, Hawthorn won the match by 38 points, putting West Coast in a precarious position on the ladder, having to rely on other teams' results to go their way for a top four finish.

[116][117] When Richmond beat the Brisbane Lions the following day, West Coast moved down to fifth on the ladder, missing out on the double chance in the finals that comes to teams that finish in the top four, making it significantly harder to win the premiership.

[43] On the day before their semi-final, Willie Rioli was provisionally suspended, effective immediately, as a result of an incident on 20 August, where he substituted his urine with another substance during a drug test.

[126][127][128] In a post-season review for AFL.com.au, Travis King rated West Coast's season a "B−", writing that "inconsistency plagued the reigning premiers", and that "the Eagles could – and should – have finished top-four".

He also said "their inability to put poor teams away cost them valuable percentage", but praised the decision to trade for Tom Hickey.