Here are the strategies to successfully beat Golem considering Golem's moveset. To see the details of Golem, such as evolution chart, CP and HP, tap the name of the Pokemon.
Moves super effective against Golem
To see the list of moves of each type, tap the name of moves below.
Golem is weak to water-type moves, so water-type Pokemon can work. However, there are better options to fight against Golem by taking moves Golem uses into account.
When the moves of Golem are all ground-type, Mud Shot and Earthquake, Fearow is one of the best Pokemon for fighting against it. While Fearow decreases the damage of ground-type moves due to its flying-type, it can use moves, Steel Wing and Drill Run, which are super effective against Golem (Steel Wing is a steel-type move, and Drill Run is a ground-type. Golem is weak to both of those types).
Grass-type Pokemons can also cut the damage of ground-type moves. Additionally, their grass-type moves can damage Golem much since Golem is weak to grass-type moves.
When the Golem's moves are all rock-type moves, for example Rock Throw and Ancient Power, Machamp is one of the best to defeat it. The damage of Golem's rock-type moves are not very effective against a fighting-type Pokemon, where as Machamp's fighting type moves are super effective against Golem.
Not only a fighting-type Pokemon, but also ground-type Pokemon can cut the damage of rock-type moves. Since many of ground-type Pokemon can use ground-type moves, which are super effective against Golem, they can have an advantage.
When the Golem's moveset is a combination of rock- and ground-type moves, fighting-type Pokemon can work well. For example, Primeape can reduce the damage of a rock-type move Golem use and can attack Golem with fighting type moves as same as Machamp described above.
Other options
Ground-type Pokemons can reduce the damage of rock-type moves. Ground-type moves are recommended to be learned since Golem is weak to those moves. Select the one you can easily get to bring in a gym battle against Golem.