Ian Durrant and Jamie Ewings (Caretakers between 8/10/2018 and 20/10/2018) Season 2018–19 was Dumbarton's first in the third tier of Scottish football for six years, having finished ninth and lost the playoffs in 2017–18.

[16] The week ended with Grant Adam becoming the club's fourth signing of the summer, joining on a one-year deal from Forfar Athletic.

[23] A day after signing Thomson marked his debut with a goal, which was added to by strikes from Calum Gallagher and Iain Russell (playing as a trialist) as Dumbarton overcame Lowland League side East Kilbride in their first friendly of the season.

[24] Russell made it two in as many games, as he scored a late winner in a 3–2 comeback victory against Cumbernauld Colts on 1 July, with fellow trialist Andy Little also on target.

[25] That form earned him a new year long deal,[26] and he made his third debut as a signed player in a 2–0 friendly defeat to Heart of Midlothian.

[28] A busy week also saw the arrival of goalkeeper Jamie McGowan, who joined having left Greenock Morton,[29] and forward Michael Paton who had impressed as a trialist against Heart of Midlothian.

That was followed by a 1–1 draw at home with Arbroath, with Ross Forbes scoring an injury-time leveler, before defeat against Brechin City, where the Sons threw away a two-goal lead with 30 minutes remaining.

[33] With the squad down to bare bones Stevie Aitken dipped into the transfer market once more – signing Spencer on a permanent deal along with Dundee United defender Scott Allardice.

Craig McPherson was appointed first-team coach a week later,[36] but a third consecutive loss followed, this time in the Scottish Challenge Cup against Montrose.

Two goals inside two minutes from Andy Dowie and Ross Forbes gave the Sons their first home league win since early April.

Brad Spencer scored his first goal as a signed player for the club a week later, but it was cancelled out by a Cammy Russell strike as Sons drew their next game against Airdrieonians.

[37] With Grant Adam injured, Sons turned to the transfer market again – bringing in Robbie Mutch on an emergency loan deal.

[38] Mutch made his debut the following day in a 3–2 defeat to Stranraer that saw Sons end the first quarter in ninth position – only ahead of Montrose on goal difference.

The inconsistent form continued into December, as Sons opened the month with a 4–1 victory against Brechin City, thanks to a brace from Calum Gallagher and goals from Ross Forbes and Dom Thomas.

A week later an injury time Brad Spencer goal rescued a point at home to Airdrieonians, before Sons lost 4–2 to Raith Rovers – conceding twice in the final two minutes.

[48] Armour made his debut the next day, starting in a 1–0 defeat to ninth placed Brechin City, where Sons conceded in injury time and played half-an-hour with ten men following the dismissal of Michael Paton.

Melingui signed a contract until the end of the season on 30 January[53] and his arrival was followed by that of goalkeeper Conor Brennan who also joined following his release by Brechin City.

April opened with Dumbarton drawing their re-arranged League One match with Airdrieonians 3-3 thanks to goals from Dom Thomas, Calum Gallagher and Ross Forbes.

Sons then recorded their first victory in three games with a 2–1 triumph against Brechin City thanks to an own-goal from former Dumbarton player Dougie Hill and a Calum Gallagher header.