Their first hit was a cover of Earl-Jean's "I'm into Something Good" which reached number one in the UK Singles Chart and number 13 in the US in late 1964. They never topped the British charts again, but they had two number one songs on the US Billboard Hot 100 with "Mrs. Brown, You've Got a Lovely Daughter" and "I'm Henry the Eighth, I Am". These songs were aimed at a US fan base, with Peter Noone (singer) exaggerating his Mancunian accent.
Their US records were released on the MGM label, which often featured their musical performers in Metro-Goldwyn-Mayer films. The Hermits appeared in several MGM movies, including When the Boys Meet the Girls (1965) and Hold On! (1966). They also starred in the film Mrs. Brown You've Got a Lovely Daughter (1968) and appeared in the 1965 anthology film Pop Gear.
The group appeared on The Ed Sullivan Show, The Dean Martin Show, and The Jackie Gleason Show. Continued success in the US proved elusive beyond 1967, although they had as many Top Ten hits in Britain in 1967 through 1970. They recorded their final album of the 1960s Rock 'n' Roll Party, and Peter Noone left the band in 1971. Herman's Hermits reunited in 1973 to headline a British invasion tour of the US, culminating with a performance at Madison Square Garden and an appearance on The Midnight Special. A later lineup with lead guitarist Derek Leckenby and drummer Barry Whitwam opened for the Monkees on their 80s reunion tours of the US. The band continues to tour today, with Whitwam as the only remaining member from the original lineup.